Updated

The Boston Red Sox are closing in on a postseason spot. The Tampa Bay Rays may be losing their grip on one. On Thursday the Rays will try to salvage the finale of their three-game series with the Red Sox at Tropicana Field.

Boston needed some late inning heroics on Wednesday, as Mike Carp's pinch-hit grand slam in the 10th inning carried the Red Sox to a 7-3 win.

Joel Peralta (2-7) walked Dustin Pedroia, who was sacrificed to second by Shane Victorino, then issued a free pass to David Ortiz before exiting for Roberto Hernandez, who walked Mike Napoli and served up the big hit from Carp, a blast to dead center for a four-run Red Sox advantage.

"Come in and do what he did, you only see that in the movies," Ortiz said of Carp. "That guy is a good hitter. One day he's going to get plenty of at-bats. He reminds me of myself when I first started. Don't get to play too much, but with a good swing."

Koji Uehara (4-0) extended his streak to 34 consecutive batters retired in a perfect ninth, while Junichi Tazawa turned in a scoreless home 10th to lock the team's seventh win in nine tries.

Napoli contributed an early two-run double for the Red Sox, who extended their lead in the AL East to 9 1/2 games over Tampa.

James Loney homered, while David DeJesus and Evan Longoria drove in a run each for the Rays, who have lost eight of their last 11. Tampa is now just one game ahead of the New York Yankees for the final wild card spot in the AL.

"You can slice and dice it, but we had chances to score way more than three runs tonight and didn't do that," Rays manager Joe Maddon said.

Getting the call for the Red Sox on Thursday will be righty Jake Peavy, who has won five of his last six decisions. Peavy, though, did not get a decision last Thursday in New York, as the Yankees reached him for four runs and six hits in six innings of his team's 9-8 win.

Since being acquired from the Chicago White Sox at the non-waiver Trade Deadline, Peavy is 3-1 with a 3.55 ERA. Overall he is 11-5 with a 4.01 ERA.

Peavy has faced the Rays five times and is 3-1 against them with a 4.99 ERA.

Tampa, meanwhile, will counter with righty Jeremy Hellickson, who is coming off his first win in more than a month. Pitching on eight days' rest, Hellickson won for the first time in seven starts on Sept. 4 in Anaheim, as he held the Angels to four hits over 5 1/3 scoreless innings to run his record to 11-8, while lowering his ERA to 5.04.

"Taking a few days off was not a bad thing -- as bad as I wanted to be out there," Hellickson said. "It definitely helped. I felt a lot fresher."

Hellickson is 4-2 lifetime versus Boston with a 4.14 ERA in 12 games (11 starts).

The Red Sox are 12-6 versus the Rays this season.