Some thought the overtime coin flip spelled doom for the Cincinnati Bengals in Sunday's AFC championship.

Surely Patrick Mahomes would march down the field like he did against the Buffalo Bills to secure a third straight Super Bowl trip for the Kansas City Chiefs. Instead, he threw an ill-advised deep ball to Tyreek Hill into double coverage that safety Jessie Bates tipped into cornerback Vonn Bell's hands for a game-shifting interception that set up Cincinnati's 27-24 win.

It was an uncharacteristic mistake from the former league and Super Bowl MVP in a massive moment. In the context of Sunday's game, it was just another miscue from a flustered quarterback who had few answers for Cincinnati's defense that prioritized pass coverage after halftime.

2 Patrick Mahomeses showed up in AFC title game

The game didn't start that way. Mahomes was in vintage form in the first half en route to touchdown passes on Kansas City's first three possessions. His first touchdown to Hill was a sidearmed laser of the variety only he pulls off. His second? More Mahomes magic via a Houdini-esque escape from pressure to find an open Travis Kelce in the end zone. It looked like the start of a long day for the underdog Bengals.

But the last play of the first half saw the Chiefs squander what looked like sure points and signaled what was coming after halftime. Facing second-and-goal from the 1, they gambled in an effort for a touchdown with 5 seconds remaining. It was an obvious situation to throw the ball away to set up a field goal if a scoring option in the end zone wasn't immediately available.

Instead, Mahomes found Hill on the sideline short of the end zone. Eli Apple tackled him inbounds, and the half ended without another touchdown or a field goal from the Chiefs. It was a moment for fans and analysts to remember in the event of a Bengals rally as the Kansas City carried a 21-10 lead into halftime.

Mistakes piled up after halftime

The Bengals rallied. And they got a lot of help from Mahomes along the way. Cincinnati forced Kansas City's first punt of the day on the opening drive of the third quarter. The Chiefs' second possession of the half ended in another punt after five plays. Their third?

Bengals defensive tackle B.J. Hill intercepted Mahomes, who sought Demarcus Robinson in the flat for a short pass in an effort to convert on second-and-3. Hill broke free from his block to pick off the pass that didn't make it to the line of scrimmage.

Five plays later, Burrow found Ja'Marr Chase for a touchdown, and a two-point conversion tied the game at 21-21. The pressure was on in a game that looked like a blowout early. Meanwhile, Mahomes continued to struggle against a Bengals defense intent on cutting off his receiving options. On a third-and-6 from midfield in the fourth quarter, Mahomes couldn't get rid of the ball in time before Trey Hendrickson found him for a sack.

Mahomes makes miscues in critical final moments

After the Bengals took a 24-21 lead, Mahomes again found himself struggling for receiving options in the red zone with a chance to retake the lead late in the final minutes of regulation. He escaped pressure the first time to eke out a 4-yard gain on second down.

There was no such luck for Chiefs fans on the next play. Mahomes held onto the ball for 11 seconds on third down while frantically looking for a receiver. Instead, he took a 15-yard loss on a sack by Sam Hubbard that forced a fumble. Only a heads-up recovery by guard Joe Thuney salvaged possession and prevented the Bengals from ending the game in regulation.

Harrison Butker's ensuing 44-yard field goal forced overtime before Bell's interception dashed Kansas City's hopes of a third straight Super Bowl.

Mahomes finished the first half completing 18 of 21 pass attempts for 220 yards with three touchdowns. After halftime? He connected on 8 of 18 attempts for 55 yards with two interceptions. He didn't find the end zone again after throwing an NFL postseason record-tying 11 touchdown passes through the first two and a half games of the postseason. His QBR in the first half? 98.0. Second half and overtime? 1.4.

So what happened?

How the Bengals flustered Mahomes

The Bengals adjusted. Per NFL's NextGen Stats, the Bengals dropped eight-plus men in coverage on 45 percent of their defensive sets on pass plays after halftime. Before halftime, they did so just 25 percent of the time. The scheme from defensive coordinator Lou Anarumo worked.

According to NextGen Stats, Mahomes finished the day completing 7 of 13 passes for 59 yards with no touchdowns and an interception when facing eight or more men in coverage. He also took two sacks in those situations.

Mahomes, Reid react

After the game, head coach Andy Reid took the blame for the last play of the first half.

“I was hoping we could get the ball in the end zone," Reid told reporters. "I probably gave him the wrong play first of all. I could’ve given him something better than that."

Mahomes also raised his hand for the blame.

“When you’re up 21-3 at one point in the game, you can’t lose it,” Mahomes said. “I put that on myself.”

He also vowed to "be back" on Twitter.

And he almost certainly will. But he'll have to come armed with a better gameplan than Sunday's. Preferably one that can deal with facing eight men in coverage.