BOSTON -- For a brief moment, the Rays were positive they were going to force the Red Sox to pack up and head back to Tropicana Field to play Game 5 of the American League Division Series.

Just moments before Boston broke out the champagne after a 6-5 walk-off victory at Fenway Park, it was Tampa Bay that was celebrating. The Rays clawed their way back from a five-run deficit, which would’ve made them the first team with at least a five-run comeback since Cleveland in Game 2 of the 2017 ALDS.

Instead, it was a rare defensive miscue by the Rays that got in the way.

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After knotting the score at 5 in the eighth, the Rays were trying to keep the momentum in their favor. Boston outfielder Alex Verdugo reached on a throwing error by shortstop Wander Franco that skipped out of play, allowing Verdugo to go to second. With one out and a runner in scoring position, Hunter Renfroe lifted a fly ball to Kevin Kiermaier in center field.

As the ball made its descent toward Kiermaier, Verdugo hustled back to second and was determined to tag up and advance. Kiermaier made the catch for the second out, then uncorked a rocket to third, where Yandy Díaz picked it out of the dirt and made the tag just in time to record the out and end the frame, ensuring that Franco’s error would not cost Tampa Bay the game.

Kiermaier’s missile of a throw clocked in at 90.0 mph -- the Rays’ third-fastest tracked throw on an outfield assist this season. And if any team would test Kiermaier’s arm in that situation, it might be Boston, which has proven that it’s not afraid to take risks on the basepaths. The club made 54 outs on the bases during the regular season, which was tied for the fourth most in the Majors (four of which were by Verdugo).

The bang-bang play was taken to a replay review, as the Rays' defenders crowded around third base, steps away from their dugout, waiting for the answer. Right fielder Randy Arozarena initially waited at his position until he saw a replay on the Fenway Park scoreboard, which prompted him to jog off the field before the umpires announced that the call stood. When the out was official, Kiermaier leaped into a Hulk-like squat, pumping his fist.

Tampa Bay was sure the momentum was going to stay in its favor.

“It's almost become an expectation that if the game is close, we're going to separate ourselves or come back and take a lead,” Rays reliever Andrew Kittredge said.

The Rays have earned the right to think this way. The team scored 220 runs in the eighth inning or later during the regular season -- 31 more than any other team. It would’ve been easy to believe they had a comeback in them.

But somehow, their defense got in their way.

The Rays have been defensively sound all season. They had 32 outs above average during the regular season, which ranked third in the Majors, behind just the Cardinals and the Astros. But this time, their late-game defense was their demise.

With one out in the ninth, a 70.3 mph slow-rolling chopper off the bat of pinch-hitter Travis Shaw caused Rays third baseman Díaz to charge toward the plate as Christian Vázquez, who was on second, broke for third. Díaz fielded the ball, and in one quick motion, he released a throw to first base without getting set. The ball skipped in front of the bag, but instead of trying to pick it out of the dirt, first baseman Ji-Man Choi threw his body in front of it like a catcher trying to prevent the ball from sailing out of play, which would have enabled the winning run to score. Choi kept the ball in front of him, but he gave up a chance of recording the second out of the inning.

“Yeah, it is a tough throw,” Rays manager Kevin Cash said. “You've got to factor in there's a guy at second base, the ball gets by, the game is over on that play. No fault at all to anybody. Yandy throws off one foot, and Ji-Man has got to secure it and keep it in front of him.

“We trust Ji-Man's judgment. He's pretty good at picking balls out that he thinks he can handle, but he felt most important to keep it in front of him.”

It all started when Vázquez singled to lead off the inning. Christian Arroyo then sacrificed him to second base. Shaw’s hustle to beat Díaz’s errant throw put runners on the corners with just one out, setting up Kiké Hernández to lift a sacrifice fly into left field to score pinch-runner Danny Santana and hand his team a walk-off victory.

“Old-school baseball right there,” Red Sox manager Alex Cora said. “Fundamental baseball, and we won the ALDS playing good fundamental baseball.”

Defense would’ve been the last thing anyone would have predicted to be the reason for Tampa Bay’s loss, but a dribbler down the third-base line proved to be the final difference-maker in the Rays’ elimination. But the team refused to allow it to hang over them.

“We were resilient all year, and guys played extremely hard through the last out,” Rays backstop Mike Zunino said. “Tip your cap. That's what I wanted to tell those guys. You left it all on the field. There's nothing to be ashamed of. When you can battle up in a game like that and tie in a 5-0 deficit is a huge positive. It just didn't work our way.”