Gregg Lovett-USA TODAY NETWORK

MIAMI — As it turns out, both teams in the Super Bowl were quite good, but the Chiefs’ offense, so-oft discussed, outlasted the 49ers’ and came back yet for the third-straight time in the playoffs in a 31-20 Kansas City win.

Twenty-one points from the Chiefs in six fourth-quarter minutes was jarring and sudden, a 20-10 lead and Super Bowl championship extinguished in the blink of a Miami minute. It started with such hope and belief and ended with heartache for San Francisco.

The 49ers opened by forcing a three-and-out on the Chiefs, which was less predictable than the fumbled-then-recovered punt return from Richie James Jr., who looks questionable at all time on punt returns.

The 49ers responded with a 10-play, 62-yard field goal drive highlighted by 39 yards of Deebo Samuel rushing (and minus-2 yards receiving. It ended with a frustrated Kyle Shanahan wondering why Jimmy Garoppolo didn’t try to extend a third-and-5 pass play at the Kansas City 20-yard line. He threw the ball away, and the 49ers took a field goal to open the scoring.

Kansas City responded by looking impossible to defend on a 15-play, 75-yard touchdown drive capped off by a Patrick Mahomes read-option touchdown run. It was a lot of speed and a lot of intelligent play design on the Chiefs’ part.

It felt like a 49ers score might be requisite to prevent that Chiefs offense from returning too quickly and running riot. But after Garoppolo threw a horribly advised pass that was intercepted by Bashaud Breeland, the 49ers defense, highlighted by two great, back-to-back tackles from Dre Greenlaw and Jaquiski Tartt, held the Chiefs to a field goal and 10-3 lead.

At that point, Shanahan had done enough to convince the Chiefs of a pass-first approach, and then zagged. And by zagged, I mean he got back to the regularly scheduled program of running the ball quite often, and quite effectively, while mixing in quick passes.

Nine yards from Raheem Mostert on a first down he had to work for. Then a quick slant to Samuel (thrown, and caught, behind him) for 16 yards. Another 11 yards from Mostert. Seventeen yards on a counter from Tevin Coleman. Samuel again on a quick pass for 11 yards. Then, the pride and joy of fullbacks everywhere, and the first Harvard graduate to score a touchdown in a Super Bowl, Kyle Juszczyk, made a catch while breaking a tackle, and evened the score at 10-10.

It was a chess match from the outset, never better exemplified than the end to the first half.

Shanahan really, really, really did not want to let Mahomes throw another pass, and really didn’t trust Garoppolo, who threw an interception on his third drive and failed to convert a key third down on his first drive. With 1:39 left in the half and the 49ers with all three timeouts left, Shanahan allowed the clock to run down to 59 seconds.

If you weren’t sold on that being the case, Shanahan followed up that clock drainage by then running the ball twice with Raheem Mostert. A Kansas City timeout stopped the clock with 20 seconds remaining with the 49ers in a third-and-5 at their own 25-yard line.

In came Jeff Wilson Jr., the guy who only converts short-yardage situations and makes game-defining play. The Elkhart, Texas, native ran an apropos Texas route just as he did on his game-winning catch (and only snap of the game) against the Arizona Cardinals in the 36-26 Week 11 win. He broke left out of the backfield, then right for a 20-yard gain, setting up the most controversial play of the game.

After Shanahan called a timeout with 14 seconds remaining, he dialed up a deep ball, which at that point was the best throw of the game by either quarterback. Garoppolo dropped an unquestionable dime into the George Kittle’s basket for a 42-yard gain down to the Chiefs’ 13-yard line. It was called by for an offensive pass interference call that looked, well, less than egregious.

There’s no debate that Kittle extended his arms, but it’s the NFL’s lack of consistency on those calls that created confusion in many minds as to whether it was warranted. With six seconds remaining, the 49ers were left to take a knee and end the half in a 10-10 deadlock.

Flag was warranted but Kittle didn't even need to push off, the defender was way overmatched pic.twitter.com/TXMuo50kBh

— new-age analytical (@benbbaldwin) February 3, 2020

That conservative approach was no doubt a result of the 49ers’ winning and deferring the opening kickoff. That first drive was another example of Shanahan subverting the Chiefs’ expectations of a steady run diet. The nine-play field goal drive featured five passes, including two to Emmanuel Sanders in tight windows (one thrown behind him on slant, the second time Garoppolo had done that) and one to Juszczyk.

The only of the four runs to go for more than four yards was another end-around by Samuel, who at that point had three rushes for 53 yards. Robbie Gould gave the 49ers a 13-10 lead after the preceding third-down play — a shallow cross from Tevin Coleman — came up a yard short.

But for as much talk as there (rightfully) was about this game being a Garoppolo vs. Mahomes affair, Garoppolo was typically fantastic after his first interception, until the late going at least.

Garoppolo on drives after he throws INT this year: 39-42 passing, 462 yards. That's freaky. Throw more picks, say 49ers' fans.

— Scott Ostler (@scottostler) February 3, 2020

Mahomes, who had never thrown an interception in his playoff career, and had eight passing touchdowns this postseason, looked an awful like Garoppolo. He never saw Fred Warner, who, playing in zone coverage (where Mahomes has been fairly praised as near-perfect this season), and made maybe the easiest catch of his career.

Legendary pick by Fred Warner pic.twitter.com/vAK9OLsaVV

— KNBR (@KNBR) February 3, 2020

The 49ers made quick work of that mistake. Garoppolo connected with Samuel for a 16-yard completion. After a two-yard run and an incompletion toward Sanders that Shanahan was furious wasn’t called for defensive pass interference, the third-down legend, Kendrick Bourne, came through for a 26-yard reception on an inch-perfect pass from Garoppolo over the middle.

Juszczyk followed that by coming up a yard short of his second touchdown of the game, disappointing every lover of fullbacks who’d ever dreamed of a fullback winning Super Bowl MVP. It’s happened once before, but not since Super Bowl VIII, 42 years ago, when Larry Csonka did it for the Miami Dolphins on 33 carries, 145 rushing yards and 2 TDs. A second Juszczyk touchdown would have put him in the MVP conversation.

Instead, it was Raheem Mostert on a one-yard rushing touchdown that gave San Francisco a 20-10 lead.

For a Chiefs team that had seemed so indefatigable, so always capable of coming back, such they were not on Sunday. Mahomes, the guy who has rightfully been described as the NFL’s next great quarterback, started to look like anything but.

He was panicking, taking sacks, making poor throws, and still, of course, completing throws and scrambling effectively, but his errors caught up with him. Nearing the 49ers’ red zone, Mahomes threw a pass behind Tyreek Hill. It bounced off Hill’s hands, and into those of safety Tarvarius Moore, who came in for a six-defensive back look. It was the second key play by Moore, who broke up a pass on the Chiefs’ third drive of the game, forcing them to take a field goal.

It represented Mahomes’ second interception of the game, something he had not done a single time this season. The last time he threw two interceptions or more was against the Los Angeles Rams on Nov. 11, 2018, when he also threw six touchdown passes and the Chiefs scored 51 points.

But Mahomes is talked about as the NFL’s next great QB for a reason. Even after struggling, throwing balls into the dirt and being limited by the 49ers’ defense, he threw the greatest pass I’ve ever witnessed in person: a 44-yard bomb thrown sideways, off his back foot, into the basket of Hill.

After the 49ers’ defensive line rushed him effectively on back-to-back plays, he came through again. First, throwing a ball that drew a defensive pass interference call on Moore against Travis Kelce, followed by a rollout touchdown to Kelce, cutting the deficit to 20-17 with 6:13 remaining in the game.

Then the 49ers’ offense sputtered and punted for the second-straight time, and with 5:10 remaining, Mahomes and the Chiefs, with three timeouts, got the ball at their own 35-yard line.

As you might expect, the Chiefs did not waste their chance. Six plays and 60 yards later, Kansas City had climbed back to take a 24-20 lead. The one saving grace from the 49ers’ perspective was that the Chiefs were so efficient, they took just 2:26 off the clock, leaving the 49ers with 2:44 and three timeouts for a final drive.

So there it was. Shanahan and Garoppolo’s chance for an iconic final drive.

It started off effectively: a 17-yard pass to Emmanuel Sanders, an 8-yard pass to Kittle, then a 16-yard pass to Kendrick Bourne.

After a batted ball and a near-interception intended for Bourne, Garoppolo launched a bomb for Sanders, who had space. Nope. The pass was long, a good few yards past Sanders and potential Super Bowl glory. Then, a Chiefs swarm and an incompletion by Garoppolo.

With 1:25, the 49ers needed three-straight stops to have any chance. Instead, Damien Williams charged in for an insult-to-injury touchdown that all but handed Andy Reid his first Lombardi trophy on a silver platter, and Williams a Super Bowl MVP nod.

31-20 … followed by an insult-to-injury interception from Garoppolo, who had a good night, except when it mattered most.

A 10-point lead turned an 11-point embarrassment. A sick, familiar feeling in Shanahan’s stomach, and the longest of flights home to Santa Clara.