ST. PETERSBURG -- The Red Sox, with some help from the Rays, had done the improbable to come all the way back from an early deficit to finally take their first lead of an eventful Tuesday night in the top of the 11th inning.

Their last line of defense for what would have been one of their grittiest wins of the season was Kenley Jansen, who came on needing three outs for the 421st save of his career.

Instead, the normally trusty righty didn’t get any. Jansen gave up a walk-off three-run homer to Brandon Lowe that handed Boston a stinging 8-6 defeat at Tropicana Field.

Jansen started his night with a walk. Up stepped Lowe, who bashed the fifth pitch of the at-bat, a cutter up and in, and walloped it down the right-field line to end a wild contest.

“That’s a tough one,” Jansen said. “Didn't get the job done. We just have to move on from this. We’ve got to keep our heads up. Got plenty of more games to play. I’ll be back out there tomorrow.”

It is highly doubtful Jansen will pitch Wednesday, no matter the situation. Tuesday marked the first time he pitched on three straight days all season.

“I mean, we were all in,” Red Sox manager Alex Cora said. “It doesn’t matter. We’re trying to win games. I don’t care what people think, four and a half, five and a half [games back], it doesn’t matter. Win that game, we win the series and we move on.”

The Red Sox will take their next crack at winning the series in the rubber match on Wednesday when rover Nick Pivetta shifts back to a conventional starter and takes the ball against Tyler Glasnow.

With Tuesday’s tough loss, the Sox (72-67) fell five games behind the Blue Jays, who leapt over the reeling Rangers for possession of the third American League Wild Card spot.

Though he didn’t come through, Jansen appreciated Cora’s “all in” mindset.

“We have to,” Jansen said. “We’re here for one thing, to try and get in the playoffs. It sucks that we lost today. As hard as it is, we just have to move on.”

Here were a couple of other notable subplots from Tuesday’s game.

Duvall’s mixed bag
Adam Duvall has been one of the hottest hitters on the Red Sox for the past two weeks. But that changed in this one, as the veteran went 0-for-5 with three strikeouts. Most glaringly, Duvall came up with the bases loaded and nobody out in the sixth and looked at a middle-middle fastball from Colin Poche for strike three.

“I felt like it was a lost opportunity for me because I’m supposed to drive those runners in,” Duvall said. “That’s how I feel right now. The big one there was with the bases loaded, I took a pitch I don’t normally don’t take for whatever reason. I was wishing I had it back.”

Duvall did provide some redemption on defense. Christian Bethancourt had a chance to end the game with a sacrifice fly in the 10th, but Duvall gathered under it and fired a bullet to the plate to nail automatic runner Lowe for an inning-ending double play.

The Red Sox took the lead, albeit briefly, in the 11th.

“I always feel like you can change the game on two sides of the ball, offense or defense,” said Duvall. “Obviously, it wasn’t my night on offense. To be able to contribute on defense, that was big. I’m still kicking myself for not driving those runners in.”

Another short start taxes ‘pen
A recurring theme reared its ugly head again for the Red Sox on Tuesday when a starting pitcher -- this time Kutter Crawford -- went fewer than five innings.

While Crawford was victimized by a couple of misplays, he also lacked command, throwing 96 pitches and walking four in 3 2/3 innings, pinning his team in a 3-0 hole in the process.

The Red Sox have received fewer than 15 outs from a starting pitcher in eight of the last 10 games. The cause and effect is an overworked bullpen. It was the second tough start in a row for Crawford, who went 2 2/3 innings and gave up six runs in his previous start against Houston.

“It’s not fun knowing your pitch count is going up because you’re not attacking the strike zone, working behind,” Crawford said. “I’m trying to get through as many innings as possible on as little pitches as possible, so I’m just frustrated at myself for not being able to command the baseball.”