ST. PETERSBURG -- Colin Poche's recent struggles continued on Tuesday as the left-hander allowed a go-ahead solo home run to pinch-hitter Christian Vázquez in the seventh inning to help the Red Sox beat the Rays, 5-4, at Tropicana Field.

After making a positive impression over the first 14 appearances out of the bullpen, Poche has struggled to find consistency. Over his last eight appearances, Poche has allowed 12 earned runs over 7 1/3 innings, and he has allowed five home runs (all to right-handers) in that span.

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"It's tough, because I feel like at times I'm throwing the ball really well. And I feel like every outing, there's a pitch or two that I miss and I'm getting burned every time," Poche said. "But I have to find a way to keep the ball in the ballpark. It's getting pretty ridiculous, honestly, how much the ball is flying out while I'm out there. There's no excuses for it, just have to go out there and be better."

Poche, who relies on a fastball that he throws 93.5 percent of the time, hasn't been able to locate his fastball up in the zone, which is when he's most effective. In the at-bat against Vazquez, Poche left a 92.5-mph fastball low in the zone and Vazquez sent it to the left-field bleachers.

"First pitch kind of went up, and I thought it would be a good idea to go back down and change the eye level," Poche said. "Kind of drove it down and it was down at the knees, but maybe middle. And he was able to go down, elevate it and take it deep."

It's the sixth time since June 12 that Tampa Bay's bullpen has allowed a go-ahead home run in the seventh inning or later. For Poche, it's the fourth time he has done so over that span.

"He's pumping strikes, that's for sure," said Rays manager Kevin Cash. "That wasn't one of those lengthy at-bats. He just left the ball down. Vazquez has had a really good year and was ready for it, and he knocked it out of the ballpark."

Boston added two insurance runs in the eighth inning off Diego Castillo and Adam Kolarek to make it 5-2.

Tampa Bay's bullpen was one of the best units in the American League over the first month of the season, but the relief corps has struggled since over their last 17 games, posting a 5.35 ERA over 69 innings, allowing 15 home runs during that stretch.

"It's one of those things where it seems like every game there's something that's not going our way," Poche said. "Baseball can be that way, and you go through stretches where things don't go your way. But I think the guys we have on this team, we have some good leaders, and I think we're going to pull through out of this."

Yonny Chirinos pitched well for the Rays on Tuesday, allowing just two runs on six hits over 5 2/3 innings and leaving with the game tied at 2. The right-hander struck out five and threw 88 pitches, 57 for strikes.

Travis d'Arnaud provided the only offense for Tampa Bay against Boston starter Chris Sale, connecting on a two-run home run in the third inning, his 11th of the season. In July, d'Arnaud has hit six home runs and 16 RBIs.

The Rays were able to put together a two-run ninth-inning rally, but Marcus Walden got Austin Meadows to ground out to first base with the bases loaded to end the game.

The Rays are now 5-6 against the Red Sox this season and have lost five consecutive games at home to Boston. Overall, Tampa Bay has lost seven of its last eight games.

"If you asked me that two weeks ago, I probably would've been more encouraged," Cash said, when asked about the late rally. "I wanna win the game. We need to win. Get the big hit, make the big pitch, we're just not doing it right now. So no, there's not too much encouragement right there."