Sunday's match at the Al Bayt Stadium in Qatar will be the first time England and Senegal have faced each other, so how good are the African champions?
Senegal, who finished second in Group A, are ranked 18th in the world - the highest of any African nation - and won their first Africa Cup of Nations in 2021 after being beaten finalists in 2019 and 2002.
They reached the quarter-finals of the World Cup in 2002 but did not qualify again until 2018, when they were knocked out in the group stage with one win in three matches.
They will be without several key players against England on Sunday, though, as Everton midfielder Idrissa Gueye serves a one-match suspension and Bayern Munich forward Sadio Mane was ruled out of the tournament because of injury.
BBC Sport and Opta have crunched the numbers to see what we could learn about maximising your chances of scoring.
Pick a side
Thinking of aiming your spot kick straight down the middle? Think again.
Take one of the first penalties
The conversion rates for the first three penalties by each team are 75%, 73% and 73% respectively. Penalty four goes in 64% of the time and number five is 65%.
Be a forward
Forwards are the most successful kickers. Failing that, be German (or Argentine).
Don't be English (or Swiss)
England have missed more penalties in World Cup shootouts than anybody else - eight (out of 19).
Video caption: World Cup 2018: Colombia 1-1 England (3-4 pens) highlightsWorld Cup 2018: Colombia 1-1 England (3-4 pens) highlights
The dreaded 'P' word: penalties.
At this stage four years ago England won their first-ever World Cup penalty shootout to beat Colombia and advance to the quarter-finals.
Their latest shootout, though, ended in defeat -an agonising loss to Italy in the final of the European Championship at Wembley last year.
Gareth Southgate says the squad have been focusing on their spot-kicks in training.
"We were not moving far from what we did, but there are some things we thought we could nail down even tighter and we have been working on that for a while," he said.
"There is a balance of not making that a bigger drama than it needs to be but, at the same time, making sure we are prepared."
'Forget style, results are the key'
England v Senegal (Sun, 19:00 GMT)
Nedum Onuoha
Former Manchester City defender on BBC 5 Live
Getty ImagesCopyright: Getty Images
They won the group, they're playing well. Being hard to beat is what got England so far in the last two tournaments. People are critical of the style of play but the results are the key thing.
If England win the final playing 10 at the back, are the people who have written the stuff about the approach, saying it needs to be nicer - going to be allowed to celebrate? Just enjoy the process because it could still end really well.
I'm in the start Phil Foden camp but it's great the amount of depth England have. Foden is an incredible player and you'd like to see him anywhere on the field but if England had won that second game, would they still be saying, 'start Phil Foden'?
I think England fans are underestimating Senegal, 100%. That's how football works, if you don't know much about the opposition because, in your eyes, they've not done much historically then you believe they're not going to be as good.
But any team that is in the round of 16 has earned the right to be there and they're the reigning African Cup of Nations champions.
Best team so far...
England
Jurgen Klinsmann
Former Germany head coach
Argentina have come into the tournament now after a poor start and, before tonight, I would have considered Brazil, but they changed almost their entire team and lost 1-0 to Cameroon. France did the same against Tunisia and also lost their own final group game, and I am not a fan of those decisions.
England though have been playing well. They had two very good performances against Iran and Wales and a professional one against the United States - that is absolutely OK, a goalless draw in the middle group game is fine.
They are scoring goals and have options in attack. So, I would say England are the best team so far.
Post update
England v Senegal (Sun, 19:00 GMT)
Here are some pictures from England training yesterday.
Spirits certainly seem high.
Getty ImagesCopyright: Getty Images
Getty ImagesCopyright: Getty Images
Getty ImagesCopyright: Getty Images
Getty ImagesCopyright: Getty Images
Post update
England v Senegal (Sun, 19:00 GMT)
Alex Howell
Football reporter in Qatar
All 25 England players trained today in Al Wakrah.
It was the last full session before they play Senegal on Sunday.
Best goal so far...
Richarlison (Brazil v Serbia)
Jurgen Klinsmann
Former Germany head coach
It was a goal that was like he was playing beach soccer, it is something that as a child he would be trying automatically.
It’s like when you grow up and try all sorts of crazy stuff. It came naturally to him – he has probably done that as a kid many times before, and then the ball comes exactly that way in a World Cup! He just follows his instinct and executes it in the same way as he would in his neighbourhood as a youngster.
It was fantastic, the kid is just so good at doing that. I saw it live as well. I was joking with my group of coaches here at Fifa that we should print out t-shirts with a picture of this goal and put the date on and say we were there!
Get Involved - your group-stage highlights
Tweet #bbcfootball, text 81111 (UK only - standard rates apply) or WhatsApp 03301231826
Now the group stages are over, we want your highlights so far. Here are some questions for you to think about:
Best goal
Best team
Best player
Best breakthrough player
Best game
Don't feel like you have to give us an answer for all of them, but the more the merrier!
You can tweet #bbcfootball, text 81111 (UK only - standard rates apply) or WhatsApp 03301231826 with your thoughts.
We've got Jurgen Klinsmann's answers and will be bringing you the best of those throughout the morning.
BreakingSenegal coach Cisse may miss England game
Getty ImagesCopyright: Getty Images
Some breaking news for you too...
Senegal head coach Aliou Cisse could miss their World Cup last-16 clash against England due to illness.
The former Birmingham and Portsmouth defender led Senegal to their maiden Africa Cup of Nations title earlier this year before guiding them out of the group stage of a World Cup for the first time since 2002.
The 46 year-old was missing from his media duties on Saturday, the day before the fixture against England in Al Khor, having also been unable to take training on Friday.
"He has been sick for a couple of days now," said assistant coach Regis Bogaert, who replaced Cisse at the press conference.
"He let us take charge of training yesterday, obviously with his instructions to the players.
"Hopefully tomorrow he will be able to come and be on the bench with the players but we are sure at 10pm he will be there with the team.
"I can confirm he is sick and has a bit of a temperature, that is why we have to be careful with his situation."
Post update
Stick with us here though.
We're going to change our focus to England, with boss Gareth Southgate and captain Harry Kane due to speak to the media at 16:00 GMT.
We'll also bring you all the latest news from the World Cup and some of the best articles from across the site.
Post update
We're going to leave our build-up to today's games there because our build-up is under way.
You can also watch the game in that page, on BBC One and on BBC iPlayer.
'We will break our backs'
Argentina v Australia (19:00 GMT)
EPACopyright: EPA
Argentina coach Lionel Scaloni - whose side are second favourites behind Brazil to win the World Cup - has complained about his side's reduced preparation time for this game.
Australia beat Denmark on Wednesday to qualify, with Argentina defeating Poland four hours later to book their place.
"Australia, who finished second in the group, played at 6pm and we finished first but played at 10pm. We went to bed at 4am and that has an impact when you have a game in 48 hours," said Scaloni, who took over after the 2018 World Cup.
"We will break our backs on this pitch to compete, we know how difficult this World Cup is, this is football."
Match facts: Will Messi find the net?
Argentina v Australia (19:00 GMT)
Getty ImagesCopyright: Getty Images
Australia's only win in seven games against Argentina was in their first meeting in 1988. Current Socceroos boss Arnold played in that match.
Argentina have reached the World Cup knockout stage for the ninth time in the last 10 World Cups.
Messi has had 23 efforts without scoring in the World Cup knockout stages for Argentina.
Australia have won consecutive matches and kept consecutive clean sheets for the first time at the World Cup. Their previous clean sheet before their two in this tournament was back in 1974.
Di Maria may be on the bench - team news
Argentina v Australia (19:00 GMT)
Argentina's Angel di Maria was taken off as a precaution against Poland because of a thigh problem so may be on the bench.
Coach Lionel Scaloni must decide between Lautaro Martinez and Julian Alvarez in attack.
Australia coach Graham Arnold could stick with the same side that beat Denmark.
Full-back Nathaniel Atkinson is pushing for a recall from the ankle knock he suffered against France.
Stoke's Souttar set for Messi showdown
Argentina v Australia (19:00 GMT)
ReutersCopyright: Reuters
Stoke City's Harry Souttar against Lionel Messi is why this World Cup is a gift that keeps on giving.
"Messi has been one of the two standout players in the world [along with Portugal's Cristiano Ronaldo], and it will be a long time until we see their likes again," says Australia defender Souttar.
"But for 90 minutes, he's just one of the players we have to face."
Live Reporting
Callum Matthews and Lorraine McKenna
All times stated are UK
How good are the Senegal football team?
England v Senegal (Sun, 19:00 GMT)
Sunday's match at the Al Bayt Stadium in Qatar will be the first time England and Senegal have faced each other, so how good are the African champions?
Senegal, who finished second in Group A, are ranked 18th in the world - the highest of any African nation - and won their first Africa Cup of Nations in 2021 after being beaten finalists in 2019 and 2002.
They reached the quarter-finals of the World Cup in 2002 but did not qualify again until 2018, when they were knocked out in the group stage with one win in three matches.
They will be without several key players against England on Sunday, though, as Everton midfielder Idrissa Gueye serves a one-match suspension and Bayern Munich forward Sadio Mane was ruled out of the tournament because of injury.
'Rest Walker ready for Mbappe'
England v Senegal (Sun, 19:00 GMT)
Thoughts?
Pick your England team
England v Senegal (Sun, 19:00 GMT)
You've seen who Alan Shearer and Rio Ferdinand would pick...
Now it is your turn.
Pick your England team for their last-16 tie against Senegal.
Ferdinand's England team for Senegal
England v Senegal (Sun, 19:00 GMT)
Shearer's England team for Senegal
England v Senegal (Sun, 19:00 GMT)
How to take a World Cup shootout penalty
Ah penalties, you have to love them. Unless you lose, in which case they are the worst thing ever.
There have been 30 World Cup penalty shootouts - with 279 kicks taken overall (excluding Diana Ross' disastrous effort at USA '94).
BBC Sport and Opta have crunched the numbers to see what we could learn about maximising your chances of scoring.
Pick a side
Thinking of aiming your spot kick straight down the middle? Think again.
Take one of the first penalties
The conversion rates for the first three penalties by each team are 75%, 73% and 73% respectively. Penalty four goes in 64% of the time and number five is 65%.
Be a forward
Forwards are the most successful kickers. Failing that, be German (or Argentine).
Don't be English (or Swiss)
England have missed more penalties in World Cup shootouts than anybody else - eight (out of 19).
Be right-footed
Sorry lefties.
And finally...
Don't be a late sub (unless you're a keeper)
Read Emlyn Begley's full insight on how to take a World Cup penalty here
'We've been working on penalties for a while'
England v Senegal (Sun, 19:00 GMT)
Video content
The dreaded 'P' word: penalties.
At this stage four years ago England won their first-ever World Cup penalty shootout to beat Colombia and advance to the quarter-finals.
Their latest shootout, though, ended in defeat -an agonising loss to Italy in the final of the European Championship at Wembley last year.
Gareth Southgate says the squad have been focusing on their spot-kicks in training.
"We were not moving far from what we did, but there are some things we thought we could nail down even tighter and we have been working on that for a while," he said.
"There is a balance of not making that a bigger drama than it needs to be but, at the same time, making sure we are prepared."
'Forget style, results are the key'
England v Senegal (Sun, 19:00 GMT)
Nedum Onuoha
Former Manchester City defender on BBC 5 Live
They won the group, they're playing well. Being hard to beat is what got England so far in the last two tournaments. People are critical of the style of play but the results are the key thing.
If England win the final playing 10 at the back, are the people who have written the stuff about the approach, saying it needs to be nicer - going to be allowed to celebrate? Just enjoy the process because it could still end really well.
I'm in the start Phil Foden camp but it's great the amount of depth England have. Foden is an incredible player and you'd like to see him anywhere on the field but if England had won that second game, would they still be saying, 'start Phil Foden'?
I think England fans are underestimating Senegal, 100%. That's how football works, if you don't know much about the opposition because, in your eyes, they've not done much historically then you believe they're not going to be as good.
But any team that is in the round of 16 has earned the right to be there and they're the reigning African Cup of Nations champions.
Best team so far...
England
Jurgen Klinsmann
Former Germany head coach
Argentina have come into the tournament now after a poor start and, before tonight, I would have considered Brazil, but they changed almost their entire team and lost 1-0 to Cameroon. France did the same against Tunisia and also lost their own final group game, and I am not a fan of those decisions.
England though have been playing well. They had two very good performances against Iran and Wales and a professional one against the United States - that is absolutely OK, a goalless draw in the middle group game is fine.
They are scoring goals and have options in attack. So, I would say England are the best team so far.
Post update
England v Senegal (Sun, 19:00 GMT)
Here are some pictures from England training yesterday.
Spirits certainly seem high.
Post update
England v Senegal (Sun, 19:00 GMT)
Alex Howell
Football reporter in Qatar
All 25 England players trained today in Al Wakrah.
It was the last full session before they play Senegal on Sunday.
Best goal so far...
Richarlison (Brazil v Serbia)
Jurgen Klinsmann
Former Germany head coach
It was a goal that was like he was playing beach soccer, it is something that as a child he would be trying automatically.
It’s like when you grow up and try all sorts of crazy stuff. It came naturally to him – he has probably done that as a kid many times before, and then the ball comes exactly that way in a World Cup! He just follows his instinct and executes it in the same way as he would in his neighbourhood as a youngster.
It was fantastic, the kid is just so good at doing that. I saw it live as well. I was joking with my group of coaches here at Fifa that we should print out t-shirts with a picture of this goal and put the date on and say we were there!
Get Involved - your group-stage highlights
Tweet #bbcfootball, text 81111 (UK only - standard rates apply) or WhatsApp 03301231826
Now the group stages are over, we want your highlights so far. Here are some questions for you to think about:
Don't feel like you have to give us an answer for all of them, but the more the merrier!
You can tweet #bbcfootball, text 81111 (UK only - standard rates apply) or WhatsApp 03301231826 with your thoughts.
We've got Jurgen Klinsmann's answers and will be bringing you the best of those throughout the morning.
BreakingSenegal coach Cisse may miss England game
Some breaking news for you too...
Senegal head coach Aliou Cisse could miss their World Cup last-16 clash against England due to illness.
The former Birmingham and Portsmouth defender led Senegal to their maiden Africa Cup of Nations title earlier this year before guiding them out of the group stage of a World Cup for the first time since 2002.
The 46 year-old was missing from his media duties on Saturday, the day before the fixture against England in Al Khor, having also been unable to take training on Friday.
"He has been sick for a couple of days now," said assistant coach Regis Bogaert, who replaced Cisse at the press conference.
"He let us take charge of training yesterday, obviously with his instructions to the players.
"Hopefully tomorrow he will be able to come and be on the bench with the players but we are sure at 10pm he will be there with the team.
"I can confirm he is sick and has a bit of a temperature, that is why we have to be careful with his situation."
Post update
Stick with us here though.
We're going to change our focus to England, with boss Gareth Southgate and captain Harry Kane due to speak to the media at 16:00 GMT.
We'll also bring you all the latest news from the World Cup and some of the best articles from across the site.
Post update
We're going to leave our build-up to today's games there because our build-up is under way.
Join Phil Dawkes for live coverage of Netherlands v USA.
You can also watch the game in that page, on BBC One and on BBC iPlayer.
'We will break our backs'
Argentina v Australia (19:00 GMT)
Argentina coach Lionel Scaloni - whose side are second favourites behind Brazil to win the World Cup - has complained about his side's reduced preparation time for this game.
Australia beat Denmark on Wednesday to qualify, with Argentina defeating Poland four hours later to book their place.
"Australia, who finished second in the group, played at 6pm and we finished first but played at 10pm. We went to bed at 4am and that has an impact when you have a game in 48 hours," said Scaloni, who took over after the 2018 World Cup.
"We will break our backs on this pitch to compete, we know how difficult this World Cup is, this is football."
Match facts: Will Messi find the net?
Argentina v Australia (19:00 GMT)
Di Maria may be on the bench - team news
Argentina v Australia (19:00 GMT)
Argentina's Angel di Maria was taken off as a precaution against Poland because of a thigh problem so may be on the bench.
Coach Lionel Scaloni must decide between Lautaro Martinez and Julian Alvarez in attack.
Australia coach Graham Arnold could stick with the same side that beat Denmark.
Full-back Nathaniel Atkinson is pushing for a recall from the ankle knock he suffered against France.
Stoke's Souttar set for Messi showdown
Argentina v Australia (19:00 GMT)
Stoke City's Harry Souttar against Lionel Messi is why this World Cup is a gift that keeps on giving.
"Messi has been one of the two standout players in the world [along with Portugal's Cristiano Ronaldo], and it will be a long time until we see their likes again," says Australia defender Souttar.
"But for 90 minutes, he's just one of the players we have to face."