Like Dragons coach Dai Flanagan said "the easiest solution for us is to win".

But should they fall short against tonight's table toppers, here are their other routes to the Challenge Cup last 16:

• Dragons win + bonus point = second in pool, 6th seeds overall, home tie

• Dragons win = third in pool, 8th seeds overall, home tie
• Dragons draw + bonus point = fourth in pool, 16th seeds, away tie
• Dragons lose = they are eliminated

George North has given Wales a Six Nations injury scare after suffering a shoulder injury in Ospreys' earlier victory against Lions.

He's flying back from South Africa this evening along with fellow Wales squad members Adam Beard and Owen Watkin.

They'll link up at Wales' training base on Monday where North's fitness will be assessed.

"He is a bit sore," said Ospreys head coach Toby Booth.

"He has a neural element in his shoulder which has shut down a little bit.

"He has got a bit of recovery time back before he gets back and we will hand over all the information to try and treat him and get him up back and running as soon as possible.

"He stayed out there and was tough which was cool to see. He has been very good with the youngsters this week. We wish him a speedy recovery."

Image source, Huw Evans Picture Agency

Dragons head coach Dai Flanagan said: "We are going out to win.

"We've won our last three at Rodney Parade. We have spoken about the importance of giving our fans stuff to cheer about, and this is another opportunity.

"In terms of qualification scenarios, we don't need to tell everyone everything. The easiest solution for us is to win whatever happens elsewhere.

"There will be conversations and interventions from me if needed during the game about what we need. It's helpful playing last."

Sharks director of rugby Neil Powell said: “The conditions here [in Wales] aren’t ideal, it’s bitterly cold and the field was frozen for our practice session, so we know it’s going to be uncomfortable for us this weekend, but we need to create our own comfort in the way we approach this game and embrace the fact that it’s going to be wet and cold.

“We’ve planned our game and week around what we can expect which is not comfortable or the best conditions, but the guys have bought into it.”

Image source, Huw Evans Picture Agency

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Dragons have made eight changes for the visit of the South African side.

Wales prop Leon Brown will make his first start of the season and will pack down against World Cup winning prop Ox Nche.

Hooker Bradley Roberts is recalled with Elliot Dee ruled out with illness.

Lock Joe Davies is paired with Matthew Screech, while Wales Under-20s captain Ryan Woodman is named at blind-side as Ollie Griffiths starts in the open-side jersey alongside number eight Aaron Wainwright.

Taine Basham is among the replacements after being left out for the last two games.

Scrum-half Dane Blacker and captain Steff Hughes return in the backline, while Joe Westwood could also make his debut from the bench.

Springboks Lukhanyo Am and Makazole Mapimpi are in the Sharks' line-up but lock Eben Etzebeth is missing.

Dragons: Cai Evans; Rio Dyer, Steff Hughes (capt), Harri Ackerman, Jared Rosser; Will Reed, Dane Blacker; Rhodri Jones, Bradley Roberts, Leon Brown, Joe Davies, Matthew Screech, Ryan Woodman, Ollie Griffiths, Aaron Wainwright.

Replacements:James Benjamin, Rodrigo Martinez, Luke Yendle, George Young, Taine Basham, Rhodri Williams, Joe Westwood, Ewan Rosser.

Sharks: Aphelele Fassi; Werner Kok, Lukhanyo Am (capt), Francois Venter, Makazole Mapimpi; Curwin Bosch, Jaden Hendrikse, Ox Nche, Fez Mbatha, Hanro Jacobs, Corne Rahl, Gerbrandt Grobler, James Venter, Jeandre Labuschagne, Phepsi Buthelezi.

Replacements: Dan Jooste, Ntuthuko Mchunu, Coenie Oosthuizen, Le Roux Roets, Tinotenda Mavesere, Grant Williams, Lionel Cronje, Rohan Janse van Rensburg.

Thanks for joining us as we bring you the second of our Challenge Cup double header.

Can Dragons emulate Ospreys' heroics in Johannesburg and book their place in the last 16 when they take on Sharks at Rodney Parade.

Dragons are fifth in Pool 1, with the top four sides qualifying for the knockout stages.

Sharks currently top of the table.

Kick-off is coming up shortly, so let's bring you the teams.

Image source, Huw Evans Picture Agency

What resilience shown by Ospreys in the final 10 minutes as they came from 28-17 down to beat Lions 38-28.

We'll be back with some post-match reaction from Johannesburg later, including an update on George North's shoulder injury.

Join us at 17:15 as Dragons take on the Sharks.

Can you fit a Sunday roast in in that time? I think you can!

Just a reminder to come back to us later for live text coverage of Dragons' decisive final pool match against Sharks at Rodney Parade as Dai Flanagan's side aim for a place in the knockouts.

Kick-off 17:30 GMT

Image source, Huw Evans Picture Agency

Stay with us while we work out the final positions and who Ospreys will face back home in Swansea.

Ospreys are now up to third in Pool 2 and they are guaranteed a home tie in the last 16 of the Challenge Cup.

The whistle goes, it's a famous victory for the Ospreys, they have won at Ellis Park.

It looked like try number five for Lions.

Jaco Visagie twists and turns from the base of the driving maul but he isn't in control of the ball as he grounds it over the line.

Lions had been on a team warning and it's the man who has just come on who sees yellow.

Hanru Sirgel is penalised for off-feet.

Ospreys haven't been able to capitalise on a man advantage before, can they do so in the last 10 minutes or so?

It's tense at Stade Aime Giral where Newcastle have levelled 16-all with hosts Perpignan.

Could the Falcons claim their first win of the season... at the 15th attempt?!

Some great off-loading by Ospreys trying to keep the ball alive, but it's a knock-on by Mat Protheroe and Lions will have the defensive scrum.

Ospreys win a penalty for off-feet and they decide to kick to touch.

The driving maul is halted but Lions concede another penalty.

They are now on a warning.

Ospreys will come again.

Ospreys get themselves back to within a score thanks to a Dan Edwards penalty.