When it was all over, Kansas City Chiefs quarterback Patrick Mahomes sprinted across the field to pay it forward. He weaved his way past the celebrating embraces of backup quarterback Chad Henne and linebacker Frank Clark, dropping his helmet at the 35-yard line and curving his trajectory to a person who had earned a shared private moment in the most public of places.

Normally, this singular path in the euphoric chaos of victory delivers a player to an embrace with family or a cherished coach. For Mahomes, it took him to another player — his mirror, in many ways.

And when Mahomes finally reached Buffalo Bills quarterback Josh Allen, he embraced him and slapped him on the back several times, speaking some private words into Allen’s ear as cameras and boom microphones engulfed them. Two competitors who see-sawed leads and traded blows in one of the greatest games in NFL history, colliding in an evening that amounted to something far greater than its considerably talented parts. Now they were sharing their mutual admiration for each other, before parting ways and leaving one to move forward while the other recedes into the inevitable hurt following an epic loss.

In the wider focus of history, it felt like a very familiar moment, one that took place almost three years to the day, when Tom Brady had frozen Mahomes out of overtime in the 2019 AFC championship game. The Patriots won the coin toss, took the ball and never surrendered it on the way to a touchdown that would keep Kansas City home in a bitter defeat. After that win, Brady went to the Kansas City locker room to find Mahomes and tell him how much he respected him, while affirming that he was on the right path to being one of the league’s best ever.

When you saw Mahomes hunt down Allen in the postgame chaos Sunday, it struck a similar chord.

These greatest games and greatest players dot the league’s history. But to become what they are — particularly for quarterbacks — one has to knock the other over along the way. That’s how the truest rivalries are born and meaningful transitions take place. This, if there was any question, is happening now.

As the book was closed on arguably the greatest weekend ever of NFL postseason football, some defining pictures continued to emerge in this postseason: First with the presumed final game of Pittsburgh Steelers quarterback Ben Roethlisberger; then to a defeated Green Bay Packers quarterback Aaron Rodgers contemplating what’s next in the final stretch of his career; and finally, on to Brady eyeing a possible end with the Tampa Bay Buccaneers.

Then came Sunday night’s juxtaposition to it all: Mahomes and Allen going toe to toe with nothing less than sheer brilliance, showcasing that the next generation of quarterbacks is ready to fill the void and expand the space to something new and exciting. They're offering a seamless graduation beyond the golden quarterback era of Brady, Roethlisberger, Rodgers, Peyton Manning, Drew Brees and many others.

Sunday’s inferno between Mahomes and Allen made that seem possible. Not only did both live up to a game that many believed could be the Super Bowl before the Super Bowl, they exceeded every expectation of it. From Allen seemingly winning the game twice in regulation to Mahomes responding each time, including teleporting a certain loss into a tie with an incomprehensible 13-second drive. Then topping that off with an overtime rip that kept Allen in the only place that he couldn’t mount yet another touchdown drive: the bench.

When the outcome was finally secured, at least three things were undeniable.

First, this was an all-time great game that will be chiseled into granite in NFL history. Maybe it will be remembered as “The 13-Second Game,” taking its place with “The Game No One Should Have Lost” between the Miami Dolphins and San Diego Chargers in 1982, “The Drive” by Denver's John Elway in 1987, “The Comeback” by the Buffalo Bills against the Houston Oilers in 1993 — or any number of others in a long list of nicknamed outcomes.

Second, Josh Allen has grown beyond simply having the physical tools to challenge Mahomes and the Chiefs for years to come. There is no “project” left in his game. He has ascended onto a plateau to rival his counterpart, and maybe even put a fork into an AFC road that seemed destined to run through Kansas City for the next decade. We looked at Allen last season and thought that was his pronounced arrival, when in fact it was this postseason. First in his dismantling of the New England Patriots, and then in his going blow for blow with Mahomes and pushing the Chiefs to the brink

And finally, Mahomes is seizing a pivotal and anchoring moment in his career right now. One that — with a Super Bowl win — would place him onto the league’s throne, regardless of what Brady does next. That’s what is at stake: A four-year run as a starter that could potentially amount to one AFC championship game loss, one Super Bowl loss and two Super Bowl wins. Few could conceive of stalking Brady’s place in history. That’s the start Mahomes would need before we start contemplating the potential longevity of his greatness.

To achieve that kind of sustained greatness, Mahomes will need others to sharpen his teeth. That’s an underrated part of quarterbacks in the NFL, the counterparts who push the best of them to work to stay at the top and also change, adapt and even learn from their staunchest challengers. Brady had Peyton Manning in the AFC for most of his career. Mahomes could have a litany coming for him in a loaded conference — from Joe Burrow to Lamar Jackson to Justin Herbert, Mac Jones and potentially others.

For now, he undeniably has one. The guy who took the lead from him and forced him to do something in the final minutes Sunday that seemed impossible. Of course, it ended badly for Josh Allen — much like it ended badly for Mahomes against Brady three years ago. But the stage is set for the two to compete for a long, long time. And when it’s finally over, the outcome will be a revelation that we all saw on Sunday:

Mahomes and Allen becoming the best thing to happen to the NFL this decade — and maybe the best thing to happen to each other, too.