Just got to keep an eye on the clock here as San Francisco take a time out - the Chiefs have it on the 37 but there's just two minutes and 48 seconds left on the clock.

Third down and San Francisco bring the heat, but Mahomes feels it and finds an open Rashee Rice who scampers away for a first down at the San Francisco 41.

Patrick Mahomes runs the ball on the designed QB keeper with Travis Kelce out in front of him as a blocker as he slides for a first down.

The Chiefs are stopped on third down and the Super Bowl comes down to this play, if San Francisco can stop them the Lombardi Trophy is theirs.

Christian Scotland-Williamson
Former NFL tight end Christian Scotland-Williamson on BBC Radio 5 Live

If Mahomes is deserving is deserving of the legacy he's trying to build, this is the drive to prove it.

Christian Wilkins, Miami Dolphins defensive tackle, on Sky Sports: It’s gametime. This is the point in the game when the defence – you give each other that look and you lock in. It’s not about what happened before, it’s about now

Osi Umenyiora, former defensive end for the New York Giants: “When you come for the king, you’d best not miss. They needed a touchdown because now the ball is with Patrick Mahomes, the best quarterback in the NFL.

“This has been an incredible back and forth game. You expect Mahomes to do something. Can the San Francisco 49ers stop him?”

Field goal - 49erspublished at 03:35 Greenwich Mean Time 12 February

03:35 GMT 12 February

San Francisco 49ers 22-19 Kansas City Chiefs

Chris Jones destroys the third down play and Brock Purdy throws it away leaving them having to kick a field goal.

Jake Moody boots it from 27 yards and now it's all on Patrick Mahomes - a field goal keeps this thing going or a touchdown to win.

Where's your money?

Jason Bell, former cornerback for the New York Giants on ITV: "Great running backs are closers. They know he's going to get the ball but they can't stop him. They talk about how hard he works in the off-season and we're seeing that right now. We're in overtime. And he is running hard. That's why they keep feeding him the ball.

"It's all on the line."

Kyle Juszczyk again takes another crucial catch and yet again a third down is converted and the Niners move inside the 10.

Can they punch this in or can somehow this weary Chiefs defence keep them out? The clock is running down too, San Francisco have had the ball for over seven minutes.

He's been quiet but Christian McCaffrey explodes down the sideline and races away to the 25-yard line against a tired looking Chiefs defence now.

They thought they had the Niners down the other end but that penalty flag has been a dagger.

Brock Purdy fires another dart over the middle and this time Brandon Aiyuk takes the catch up near midfield for another huge third down conversion.

Steve: This game hasn't been a classic..... but this end game will now make it into one.

Oh wow, that's a massive penalty on Chiefs cornerback Trent McDuffie after Brock Purdy had a pass batted down, the Niners had to punt but that penalty gives them a fresh set of downs.

That could genuinely change the outcome of the game - Super Bowls are decided by small margins, overtime Super Bowls are decided by microscopic ones.

Greg Brady
NFL pundit on BBC Radio 5 Live

Would Kyle Shanahan be able to stomach being a two-time overtime Super Bowl loser? That'd take till late in the summer to recover from.

Ben Collins
BBC Sport

This is just the second Super Bowl which has gone to overtime.

The first came as the New England Patriots produced a record comeback before beating the Atlanta Falcons in 2016.

The Falcons' offensive coordinator that day? The current 49ers head coach Kyle Shanahan.

Oh wow! Nick Bolton, who had a pick six in last year's Super Bowl, almost had an interception after Deebo Samuel bobbled a catch - the ball actually went through Bolton's hands as he dived forward.

So close.

Here we go then, the biggest drive of Brock Purdy's young career - biggest one since the fourth quarter one a few minutes ago.

San Francisco win the toss and want the ball first, so Kansas City will kick off in a couple of moments. Talk about drama, this is as tense as it gets.

Kyla Shanahan knows all about that, he was involved in the only other Super Bowl overtime when offensive coordinator of the Atlanta Falcons when they lost that epic against the Patriots.

And that's that. We've had 60 minutes but they can't be separated in Las Vegas so we're going to overtime.

It's the first post-season game with the new rules so both teams will have a chance to have the ball - even if the team with it first scores a touchdown the other side will have the chance to answer.

If we're level after both sides have had the ball then we're into sudden death.