Mike Carp spent more than a month on the disabled list with a broken right foot. He watched the Boston Red Sox struggle, wishing he could contribute.

Sometimes, he couldn't bear to watch.

"Some of the nights, I almost had to turn the TV off in those situations because you can't be there to help," Carp said. "It's tough being on the DL with a boot on my foot."

He was smiling Thursday after delivering a pinch-hit single in the 10th inning that gave the Red Sox a 4-3 win, their second consecutive walk-off victory over the Chicago White Sox.

"Happy times," said Carp, who was on the disabled list from June 2 until being activated Monday.

There haven't been many of those this season for the Red Sox, the defending World Series champions who are in last place in the AL East. With two straight wins to end their 3-7 homestand, they head to Houston for a three-game series with a chance to build some momentum going into the All-Star break.

"Hopefully it'll get us in a little bit of a rhythm, comfort level," said left-hander Jon Lester, who allowed one run and struck out 12 in seven innings. "A win like today is huge."

Lester gave up seven hits and no walks. In his last six starts, he's 3-0 with a 1.01 ERA, 39 strikeouts, six walks and 33 hits allowed in 44 2-3 innings. He extended his streak to 45 innings without giving up a homer.

But fellow All-Star Koji Uehara allowed a tying, two-run homer in the ninth to pinch-hitter Conor Gillaspie — his third long ball in three games and fourth of the season.

"He's been hotter than all get-out lately," teammate Adam Eaton said.

David Ortiz had a two-run double that gave the Red Sox a 3-1 lead in the sixth after Jose Quintana retired Boston's first 15 batters.

"I really wanted to win this game because (Lester's) a really good pitcher," said Quintana, whose scoreless streak ended at 20 2-3 innings, "but I had one bad inning in the sixth."

Pinch-hitter Daniel Nava started the winning rally with a leadoff walk and went to second on a sacrifice by Mookie Betts. Stephen Drew, in an 0-for-15 slump, was intentionally walked by Ronald Belisario (3-6).

Carp, who had been 0 for 2 as a pinch hitter in the series, then batted for David Ross and lined a single between shortstop and third base. Nava scored the winning run for the second consecutive game, and Carp was mobbed by teammates rushing out of the dugout.

In Boston's 5-4 comeback victory Wednesday night, Nava doubled in Betts for the tying run in the ninth and scored on Brock Holt's single.

Chicago had runners at first and third with two outs in the 10th, but Alexei Ramirez was retired on a grounder to pitcher Andrew Miller (3-5).

Ramirez led off the ninth with an infield single — after first base umpire Cory Blaser's out call was reversed on replay. Uehara then struck out Paul Konerko before Gillaspie, batting for Moises Sierra, homered.

Lester trailed 1-0 after three batters. Eaton singled, Gordon Beckham struck out and Jose Abreu hit an RBI double over a leaping Jonny Gomes in left field. Lester then struck out Dayan Viciedo.

Lester fanned two batters in each of the first five innings and one each in the sixth and seventh before being replaced by Junichi Tazawa, who pitched a perfect eighth.

Uehara failed to hold the lead, though, his second blown save in 20 chances this season.

Boston went ahead in the sixth when the first three batters reached base on full counts.

Drew became Boston's first runner with a walk and went to second on a walk to Ross. Jackie Bradley Jr. attempted to bunt on the first four pitches, then took a ball to bring the count to 3-2. He grounded a single to right field for Boston's first hit, driving in Drew with the tying run.

The next two batters were retired before Ortiz's two-run double.