San Francisco 49ers quarterback Jimmy Garoppolo rued being unable to produce a game-winning drive in Super Bowl LIV as the Kansas City Chiefs emerged victorious 31-20 in Miami.

The Niners threw away a 10-point lead midway through the fourth quarter, Patrick Mahomes throwing touchdown passes to Travis Kelce and Damien Williams to put the Chiefs ahead.

Garoppolo got the ball back with 2:39 to go on the San Francisco 15 with the Niners four points down, and a touchdown drive would surely have quelled the doubters who believe he is not a franchise quarterback.

However, Garoppolo could only get his team to midfield, missing Emmanuel Sanders on a long-third down throw and then being sacked on fourth down.

Williams ran in another score to put the result to bed and Garoppolo threw a second pick to Kendall Fuller in a game where he finished 20-of-31 passing for 219 yards, one touchdown and two interceptions.

Asked about being unable to deliver a game-winning moment, Garoppolo replied: "Those are the moments you dream of and everything.

"We got rolling on a right note and just couldn't finish it off. 

"It is tough but it's been a hell of a year with these guys. Everything we have been through from the start, it's an incredible story."

Garoppolo was a two-time Super Bowl winner as Tom Brady's backup with the New England Patriots, but this time he was on the losing side as the starter in San Francisco.

"It's tough, I mean, I've never had this feeling before," he said.

"Kind of an unreal feeling."

San Francisco, and their swarming defense, had appeared in control of the contest before Mahomes delivered some fourth-quarter magic.

Tight end George Kittle, who finished with four catches for 36 yards, added: "It's pretty brutal.

"It just honestly sucks. It's not really anything you can wrap your head around. I feel like I wish I had another half to play, but I don't.

"We didn't take advantage of our opportunities. I wish we had another page in the book. We just didn't get it done."