Patrick Mahomes of the Kansas City Chiefs celebrates after defeating the San Francisco 49ers in Super Bowl LIV on Sunday in Miami. Photo: AFP

Running back Damien Williams scored two touchdowns, one by air and one by land, and Patrick Mahomes also threw a touchdown to tight end Travis Kelce in a three-touchdown fourth quarter that brought the Kansas City Chiefs back from a 20-10 deficit to defeat the San Francisco 49ers 31-20 in Super Bowl LIV on Sunday.

It was Kansas City's first Super Bowl victory in 50 years.

Mahomes finished 26 of 42 for 286 yards (261 meters) and two touchdowns with two interceptions, while being named the game's Most Valuable ­Player. He threw for 141 yards in the fourth quarter and became the second-­youngest quarterback ever to win a ­Super Bowl at 24. Ben Roethlisberger led the Pittsburgh Steelers to win Super Bowl XL at 23 in 2006.

"We never lost faith, I think that's the biggest thing," Mahomes said afterward on the Fox broadcast. "Everybody on this team, nobody had their heads down."

Things looked bleak for the Chiefs when Mahomes was sacked twice and intercepted twice in the first 18 minutes of the second half, as the 49ers gained a 20-10 lead after the score was tied 10-10 at halftime.

However, the Chiefs - who rallied from deficits of 24-0 to Houston and 10-0 to Tennessee earlier this postseason - started their comeback on a 10-play, 83-yard drive. They pulled within 20-17 on a 1-yard touchdown pass from Mahomes to Kelce with 6:13 to play.

After a 16-yard apparent completion to receiver Tyreek Hill was reversed on replay, Mahomes connected with Hill on a 44-yard pass to the 49ers 21-yard line.

The ball went to the 1-yard line when safety Tarvarius Moore was flagged for interference on Kelce in the end zone. Moore had registered Mahomes' second interception of the game that stopped a Kansas City drive that reached the 49ers 23-yard line.

However, the Chiefs forced the 49ers to punt after the interception, which led to the Kelce score.

"It's 'Magic Mahomes,' it's 'Showtime Mahomes,'" Kelce told reporters. "He willed this team back into the game."

The 49ers then had their first three-and-out of the game when linebacker Ben Niemann pressured 49ers quarterback Jimmy Garoppolo, forcing an incompletion on a third-and-five play. Mahomes then engineered a seven-play, 65-yard scoring drive that featured a 38-yard completion to wide receiver Sammy Watkins to the San Francisco 10-yard line. They took a 24-20 lead on a 5-yard pass to Williams.

"It was Pat Mahomes and the defense taking care of business," Chiefs head coach Andy Reid, who won his first Super Bowl in his 222nd career victory as a head coach, said afterward.

"Coach Reid told me after both of 'em to keep firing," Mahomes said. "Keep believing and keep firing."