BOSTON (AP) -- Boston's Jonny Gomes led off the ninth inning with a home run, lifting the Red Sox to a 2-1 victory over San Diego on Wednesday which maintained their lead atop the American League standings.
Gomes sent a pitch from Luke Gregerson (4-4) over Fenway Park's Green Monster for his second game-ending homer of the season.
Elsewhere, Jeff Locke won his eighth-straight start to guide Pittsburgh past Philadelphia, St. Louis ended the Los Angeles Angels' seven-game winning run, and Detroit pitcher Max Scherzer improved his season record to 13-0 as the Tigers beat Toronto.
Cincinnati beat San Francisco in 11 innings, Seattle needed 10 to get past Texas, and Kansas City edged Cleveland after losing Alex Gordon to a head injury.
Boston's Mike Carp had two hits and scored a run as the Red Sox improved to 7-1 on its nine-game homestand that concludes Thursday against the Padres.
San Diego has scored just five runs in its five-game losing streak.
Pittsburgh's Locke (8-1) was in command as the majors-leading Pirates hung on for a 6-5 win over Philadelphia.
Locke was scored upon for the first time in four home starts but extended his unbeaten streak to 16 outings. He allowed two earned runs over 5 2-3 innings.
The Pirates took the lead with a four-run fifth inning punctuated by Pedro Alvarez's three-run homer.
Domonic Brown's two-run homer with two outs in the ninth pulled the Phillies within one run, but Jason Grilli stuck out Delmon Young to end it and seal his NL-best 28th save.
St. Louis cut loose with a seven-run second inning -- in which Jon Jay had three RBIs, including a two-run homer off the center fielder's glove -- to set up a 12-2 win over the Los Angeles Angels.
Matt Carpenter, batting leadoff in front of Jay, also homered and drove in three runs to help keep the Cardinals two games behind Pittsburgh in the NL Central.
Cincinnati's Shin-Soo Choo hit a two-out single in the 11th inning to drive in Todd Frazier from second base and give the Reds a 3-2 win over San Francisco.
Frazier walked to lead off the 11th against Javier Lopez (1-1) and went to second on a sacrifice. After an intentional walk then pop out, Choo came through with the winning hit to give the Reds three straight wins for the first time in three weeks.
The spiraling Giants have lost nine of their past 10 games.
Detroit's Max Scherzer became the first pitcher in 27 years to start a season 13-0 as he guided the Tigers to a 6-2 win over Toronto.
Scherzer allowed two runs, struck out eight and walked one in 6 1-3 innings. The last man to start 13-0 was Roger Clemens for Boston in 1986, who won his first 14 decisions.
Both benches and bullpens emptied after Tigers outfielder Torii Hunter took exception to being hit by a high pitch from Todd Redmond in the sixth.
Seattle's Kyle Seager hit a two-run homer in the 10th inning to lift the Mariners to a 4-2 win over Texas.
Michael Saunders walked on a full-count pitch with two out before Seager connected against Robbie Ross (4-2) for his third hit of the game.
Kansas City's Eric Hosmer hit a go-ahead homer in the seventh inning and the Royals hung on for a 6-5 win over Cleveland.
Hosmer connected with two outs off Cody Allen (3-1), one inning after outfielder Nathan Gordon collided with the bullpen fence while tracking a fly ball. He remained down for several minutes before slowly standing and walking off the field.
The Indians had won their previous five.
Chicago's Matt Garza pitched eight sharp innings for his third consecutive win, helping the Cubs down Oakland 3-1.
Baltimore's Chris Davis hit his major league-leading 32nd homer of the season, and then added a tiebreaking two-run double in the eighth to almost single-handedly lead the Orioles to a 4-2 win over the Chicago White Sox.
New York's C.C. Sabathia earned his 200th career win to stretch his winning streak over Minnesota to nearly six years, guiding the Yankees to a 3-2 win over the Twins.
Los Angeles' Hanley Ramirez had four hits, including a solo homer in the ninth, to help the Dodgers defeat Colorado 10-8.
Miami's Ricky Nolasco tossed seven strong innings amid persistent trade rumors, steering the Marlins to a 6-3 win over Atlanta.
Arizona's Randall Delgado outpitched Matt Harvey for his first major league win in more than a year as the Diamondbacks snapped a five-game skid with a 5-3 victory over the New York Mets.
Houston's Chris Carter hit a tiebreaking three-run shot in the seventh inning for his second homer of the game, leading the Astros to a 4-1 victory over Tampa Bay.
Milwaukee's Kyle Lohse tossed eight sharp innings on short rest to help the Brewers record a 4-1 win over Washington.