KANSAS CITY, Mo. — Patrick Mahomes was just trying to run out of bounds, not make the kind of shake-your-head, what-did-he-just-do play that will be shown on highlight reels for as long as the Kansas City Chiefs are in existence.

It was late in the second quarter of the AFC championship game, and the Chiefs were trailing Tennessee 17-14. Mahomes had already marched them nearly the length of the field, giving Kansas City at worst a chance for a tying field goal, when he scrambled from the pocket and headed toward the sideline with every intention of avoiding any kind of hit.

Then he made a defender miss and saw nobody in front of him, so he turned upfield instead. Mahomes barrelled toward the goal line and right over one defender, then spun away from two more, and crashed into the end zone for the go-ahead score.

The momentum of his TD run would spur the Chiefs to two more fourth-quarter touchdowns and a 35-24 victory, and into their first Super Bowl in 50 years. And the play itself showcased why defending Mahomes is so difficult: Even when his pass catchers are covered, the young quarterback can still beat opponents on the ground.

“They have the ultimate respect for him,” Chiefs coach Andy Reid said of defences, “and they're doubling our guys. You're not just getting one guy double but two, and the defensive line is trying to sack him. So if he makes one guy miss, it's over. He has all this running space. We've seen that the last couple weeks. For him to be able to see it, decipher it and go — it's just part of the game for him. You don't have to tell him anything that he doesn't already know.”

Except maybe to slide. That has been a work in progress, and Mahomes has been much more savvy about getting down before taking a big hit. But he wasn't going to do that last Sunday, when a trio of Titans were all that stood between Mahomes and the end zone after a 27-yard highlight-reel scramble.

“As I got to the sideline,” he recalled last week, “I realized I could cut up. I was running down the sideline and I knew we had two timeouts, so I might as well try to cut it back. I cut it back, and luckily I was able to hold on to the ball and get into the end zone.”

It was the kind of improvisational play that could come in handy against the San Francisco 49ers' stingy defence in the Super Bowl, and the kind of play that Mahomes might not have been able to make for much of this season.

The reigning league MVP sprained his ankle in a season-opening win at Jacksonville, and that caused him to hobble a bit for the next few weeks. Then in Week 7, on a benign quarterback sneak, Mahomes dislocated his kneecap and missed the rest of that game and the next two. And when he returned, he still wasn't close to 100%.

But the Chiefs' bye this season didn't come until Week 12, and that turned out to be fortuitous. Mahomes got a chance to more fully recover, and he came back for the stretch run the healthiest he'd been all season.

It has shown in the playoffs, too. Mahomes has led the Chiefs in rushing in each of their two wins, setting career highs each time. The big run against the Titans was about half of his 53-yard total, and his total was just 16 yards shy of what bruising Titans star Derrick Henry managed against the revamped Kansas City rush defence.

“I think his running ability adds a lot,” Chiefs offensive co-ordinator Eric Bieniemy said. “First of all, it tells a lot about how Pat sees things. I know Pat recognizes the coverages that teams are playing, and doubling (Travis) Kelce and (Tyreek) Hill, and the thing he recognizes is nobody is on him, so he takes off and runs.”

Bieniemy did pull Mahomes aside after his TD run against Tennessee, but it wasn't to admonish him for refusing to slide or step out of bounds. Instead, it was to provide the kind of advice one would expect from a former runner back: "I just said, ‘Hey, if you're going to keep running for us, let's talk a bit about ball security.'”

The Chiefs certainly would prefer their running backs — Damien Williams, Darwin Thompson and LeSean McCoy — did most of the heavy lifting in the ground game against San Francisco. But they aren't about to curtail Mahomes' competitive fire, even when it manifests itself in running the ball — and especially when it seems to be working.

“His understanding of space and understanding of coverage is incredible,” offensive tackle Mitchell Schwartz said. “Most guys look at a play, ‘Oh, that's good. Let's do that.' But he understands coverages and, ‘We can do this because this guy is here and we can exploit him.’ It's pretty awesome."

___

More AP NFL: https://apnews.com/NFL and https://twitter.com/AP_NFL