Jose Iglesias came through with a key two-run, eighth-inning hit, as Boston used a late charge to down Tampa Bay, 6-2, in the second edition of a four-game set from Fenway Park.
Stephen Drew, Mike Carp and Dustin Pedroia drove in a run each, while Mike Napoli added two hits and scored twice for the Red Sox, who overcame a loss in Monday's opener and won for the third time in five games.
Jon Lester (9-6) worked 6 1/3 innings for the win, giving up two runs on seven hits with eight strikeouts, helping Boston extend its lead once more to 1 1/2 games over Tampa in the AL East.
"You never want to diminish any start," Red Sox manager John Farrell said. "But again, where we are in the standings, where they are, knowing we're only still in July, but this was a big game for us tonight. It was probably as powerful as he���s been all year."
Wil Myers and Evan Longoria each clubbed a solo homer for the Rays, who suffered just their third loss (16-3) in the month of July.
"If we continue to play good baseball we're going to be just fine. We did play good baseball tonight, a couple of really unfortunate moments towards the end of the game," Rays manager Joe Maddon said. "Overall I am not displeased. I think we're doing a great job."
Roberto Hernandez (5-11) was tagged in defeat for seven hits and three runs over his five-inning outing.
The Red Sox picked up valuable insurance runs in their final turn at the plate in the eighth, stretching a one-run edge to four.
Napoli doubled with one out and Jonny Gomes followed with a single. Two batters later, Drew slid a ball through the right side to make it 4-2 and left runners on the corners. After Drew swiped second, Iglesias' hit to short got through the infield and was slow enough to bring both men home for a 6-2 lead.
Koji Uehara then clinched the game with a perfect ninth that included a pair of strikeouts.
Myers reached the light tower above the Green Monster to kick off the second inning, but three straight singles in the home half -- the last one from Carp -- brought in Napoli.
Shane Victorino began the third with a double, advanced on a fly from Daniel Nava, then after Pedroia was plunked, scored when the hosts successfully executed a double steal.
The Sox pushed the lead to 3-1 in the fifth, after Nava doubled with one down, moved to third on a wild pitch and crossed the plate on a Pedroia fly to right.
Longoria's blast to left center pulled the Rays within 3-2 to begin the sixth, but Lester kept the lead until Jose Molina's one-out double chased him in the seventh.
Matt Thornton and Junichi Tazawa closed out the frame, then Tazawa turned in a scoreless eighth.
Boston improved to 6-2 at home against the Rays this season and lead the season series 10-4 ... The last time a double steal, including home plate, was executed by the Red Sox was Oct. 3, 2010, when Ryan Kalish scored ... Prior to the contest, MLB announced that Rays Double-A catcher Mark Thomas received a 50-game suspension without pay after a second violation of the Minor League Drug Prevention and Treatment Program for a drug of abuse ... Also prior to the game, reports surfaced that Pedroia was signed to a seven-year contract extension worth $100 million.