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Edinson Volquez won a few bucks on his 30th birthday.

The rest of his San Diego teammates weren't as lucky.

Volquez held Boston to one run over six strong innings before Luke Gregerson surrendered a game-ending homer in the ninth to pinch-hitter Jonny Gomes that sent the Red Sox to a 2-1 victory over the Padres on Wednesday night.

Carlos Quentin went 3 for 4 with a double and two singles for San Diego, which has lost five straight, scoring just five runs during the skid.

"Little bit up in the strike zone," San Diego manager Bud Black said of Gregerson's 2-2 slider that Gomes sent into the stands. "Threw a couple of good ones down that Gomes swung through. I'm sure he tried to execute the same one that he did the previous two for strikes, just left it a little bit up.

"Gomes was probably looking for it."

Pitching on his birthday for the first time in his nine-year career, Volquez scattered seven hits with six strikeouts and just one walk, an intentional one to David Ortiz in the third inning.

He has allowed three earned runs or less in each of his last five starts, going 2-1 with a 2.73 ERA during that stretch.

"It was a gutty performance by Eddie," Black said. "I liked the no walks, for sure."

Volquez said he made a bet with pitching coach Darren Balsley on how many walks he'd surrender against Boston.

"I won some money with that," he said with a laugh.

Gregerson (4-4) jumped ahead 1-2 before Gomes evened the count and hit his second game-ending homer of the season, sending Gregerson's fifth straight slider into the first row of seats above the Green Monster in left field.

"He pitched very well in Miami. Really good sliders down there against some of their hitters," Black said. "I thought a really good slider today, too.

"It just so happens tonight where he got one up, the guy got a hold of it."

Mike Carp had two hits and scored a run for Boston, which is 7-1 on its nine-game homestand that concludes Thursday against the Padres.

Koji Uehara (2-0) pitched one inning for the win.

The Red Sox squandered a good chance in the eighth. Dustin Pedroia led off with a double off the Green Monster against Nick Vincent. After Ortiz was intentionally walked for the second time, Gregerson relieved and retired the next three batters, striking out Daniel Nava and Jarrod Saltalamacchia.

Boston's Jon Lester had a similar line to Volquez over seven innings, allowing six hits, one run, walking one and striking out five. He entered just 2-4 with a 6.98 ERA in his last eight starts.

Lester labored in the first, throwing 32 pitches and giving up a run. Plate umpire Doug Eddings called time just as Lester was starting to throw a pitch to Chase Headley. It hit him on the foot, but was waved off. Headley then proceeded to have a 10-pitch at-bat, reaching on a single. Kyle Blanks followed with an RBI single to center.

Boston tied it 1-1 when Carp singled leading off the fourth and scored when left fielder Quentin misplayed a carom off the Green Monster on Saltalamacchia's double.

Lester eventually settled down, retiring the Padres in order on just five pitches in the second. He gave up a hit, but needed only 12 in the third.

Volquez struck out the side in the second after allowing Carp's leadoff single.

Both dugouts were warned by Eddings after Volquez hit Jose Iglesias with the first pitch in the third inning.

"Every run that the bullpen gives up, it's magnified. Or anytime a bullpen does a good job it's magnified in the positive," Black said. "It's a tough role because at either time it's goat or hero. That's what makes this game great and exciting and emotional all at one time."

NOTES: Red Sox RHP Clay Buchholz, on the 15-day since June 9 with a neck strain, threw from flat ground at about 100 feet. Buchholz was 9-0 with a 1.71 ERA before the injury. ... The Padres made a lineup change about three hours before the game, moving Quentin from DH to left field and Blanks from left to DH. ... Red Sox manager John Farrell gave 1B Mike Napoli a rest and inserted Carp at first, batting him sixth. .Quentin was 0 for 11 in his career against Lester. ... Boston SS Iglesias was named AL rookie of the month for June, the first Red Sox player to win it since Jacoby Ellsbury did it in Sept. 2007. Iglesias hit .395 in 25 games. ... Game time temperature was 87 degrees with a steamy feeling in Fenway.