Bills Chiefs Football

Kansas City Chiefs quarterback Patrick Mahomes (15) celebrates with fans as he walks off the field after an NFL divisional round playoff football game against the Buffalo Bills, Sunday, Jan. 23, 2022, in Kansas City, Mo. The Chiefs won 42-36 in overtime. (AP Photo/Colin E. Braley)

KANSAS CITY, Mo. (AP) — There was never a sense of panic for Patrick Mahomes as he stood on the sideline Sunday night, watching the Bills score yet another late touchdown to regain the lead with 13 seconds left in their divisional-round game against the Chiefs.

Thirteen seconds? With plenty of timeouts?

No cause for concern.

By now, everyone knows what happened next: Mahomes flipped a quick pass to Tyreek Hill and stopped the clock, then found Travis Kelce running down the seam and stopped the clock again. The Chiefs had gone 44 yards and still had enough time to send Harrison Butker out for a 49-yard field goal that pushed the game to overtime.

The Chiefs won the coin toss, marched downfield and won the game.

"I think it's a little bit of a couple things," Mahomes said. "First off, I've been in some of these situations before now. I've played in some big games, had to make some comebacks, and I have the teammates to do it. I know what it takes to go out there and find a way to win. I think just preparation — I mean, we prepare for those moments the whole season.

"I think preparation and experience definitely helps you in those moments."

Plenty of quarterbacks have experience, though. All put in endless hours studying film and on the practice field. And yet few of them are able to march downfield with 13 seconds left as calmly as Mahomes did Sunday night.

Just think back to the previous weekend, when Cowboys quarterback Dak Prescott was marching downfield in the final minute in search of a winning touchdown against San Francisco. Prescott took off on a scramble with 14 seconds left and made it to the 49ers 24-yard line, but time expired before he was able to snap the ball again.

To recap: Prescott got 16 yards for his team in 14 seconds. Mahomes got 44 for his team in 13.

"We have a ton of confidence in what he can do," Chiefs left tackle Orlando Brown Jr. said. "Fifteen is great and he's very poised, and I've got a lot of trust in him. I just want to do my job to make sure we can execute as an offense."

There are metrics that back up Mahomes' poise, too.

His trainer at Team APEC in Texas, Bobby Stroupe, released the data from the heart-rate monitor that Mahomes was wearing during the Bills game. It showed that his heart was beating its slowest when he was in the huddle — right in the middle of a cavern of noise and with the season on the line, or what Stroupe called his "flow state."

By contrast, Mahomes' rate spiked in two situations. The first was after the Chiefs pulled off a big play, such as his 64-yard TD pass to Hill with 1:02 left to regain the lead; his heart rate hit 171 beats per minute.

The second came after Buffalo had answered with a touchdown of its own, even though Mahomes was merely watching from the sideline.

On the winning drive in overtime, Mahomes's heart rate hovered around 150 beats per minute. It wasn't until he found Kelce in the corner of the end zone that it maxed out at 169 beats amid the thrill of victory.

"Down in here," Chiefs coach Andy Reid said, pointing to his heart, "he's gritty and he wants to get after you every opportunity he has. Most of all, he wants to be great, and he wants everyone around him to be great. He has the ability at that position to do that, and he's not afraid to be coached. He's not afraid to be studied hard. He's not afraid to work out hard, go the extra mile with diet, strength training, all those things — flexibility — he does it all the best he can.

"What we've seen," Reid continued, "we've been spoiled with for the last few years. He's a pretty spectacular player and we are lucky to have him right here in Kansas City. To have the grit, I think that tells you a little bit about him."

NOTES: FS Tyrann Mathieu returned to practice Thursday for the first time since sustaining a concussion on the opening drive against Buffalo. Mathieu still must pass a series of post-practice tests to be cleared to play Sunday, but the Chiefs are optimistic that he will be available. "I thought he did a nice job, moved around well. He was fine today," Reid said, "so he's just got to go through the protocol here, finish that up, make sure he's OK."