Patrick Mahomes led a thrilling late comeback as the Kansas City Chiefs ended their 50-year wait for a Super Bowl crown with a 31-20 victory over the San Francisco 49ers on Sunday.

Chiefs quarterback Mahomes shrugged off an error-strewn start to overturn a 20-10 fourth-quarter deficit in a nail-biting battle for the Vince Lombardi Trophy at the Hard Rock Stadium in Miami, Florida.

The Super Bowl win was Kansas City’s first NFL Championship since their triumph over the Minnesota Vikings in 1970.

And it owed everything to the nerve of Mahomes, who for the third straight postseason game led the Chiefs back from a double-digit deficit to seal a dramatic win.

“We never lost faith. Everybody on this team, no one had their head down and we found a way to win in the end,” said Mahomes, shortly before being anointed Super Bowl’s Most Valuable Player.

The Chiefs quarterback had looked out of sorts until early in the fourth quarter, throwing two interceptions in the face of fierce pressure from the magnificent San Francisco defense led by the marauding Nick Bosa.

But with the game on the line in the fourth quarter, Mahomes led his team on two long drives to set up touchdowns for Travis Kelce and Damien Williams.

Those scores put the Chiefs into a 24-20 lead and Kansas City made the game safe when Williams danced up the sideline for a 38-yard rushing score with 1min 12sec remaining.

Mahomes finished with 286 passing yards and 26 completions from 42 attempts with two touchdowns. The Chiefs quarterback also rushed for a touchdown early in the first quarter.

But the defeat was desperately hard on the 49ers, who were chasing a record-equalling sixth Vince Lombardi Trophy.

The 49ers had barely put a foot wrong through three quarters, with their defense shackling Mahomes superbly and their offense moving the ball confidently to put them in the driving seat late in the game.

“They have an amazing defence,” Mahomes said afterwards. “We weren’t executing at a high enough level, and when you play a defense like that, you’re not going to have success.”

Garoppolo cracks

But as the pressure in the fourth quarter mounted, 49ers quarterback Jimmy Garoppolo’s sure touch deserted him and the Niners offense dried up.

With Mahomes leading the Chiefs on two long drives to engineer a 24-20 lead, Garoppolo had one last chance to lead the 49ers on a game-winning drive with 2min 44sec remaining.

But the Chiefs defense suddenly began to find gaps to pressure Garoppolo, and give possession back to Kansas City, the writing was on the wall.

Two plays later Williams then drove the final nail into the 49ers coffin, finding space down the left hand touchline and galloping into the endzone for a score to make it 31-20.

Garoppolo was then intercepted on the next 49ers possession and it was left to Kansas City to run down the clock for victory.

The win was a long-awaited first Super Bowl triumph for Chiefs head coach Andy Reid, the 61-year-old veteran long regarded as the best NFL coach not to win a championship.

But the fourth quarter collapse was cruel on 49ers coach Kyle Shanahan.

Shanahan had been the offensive co-ordinator for the Atlanta Falcons at the 2017 Super Bowl when they let a 28-3 lead slip in a stunning loss to the New England Patriots.