Athletics 2, Pirates 1: Bartolo Colon allowed one run in seven innings to pick up his 12th win as visiting Oakland took the opener of the three-game series.

Colon (12-3) gave up seven hits and pitched out of a pair of jams to improve to 9-1 in his last 10 starts. Ryan Cook worked out of trouble in the eighth before Grant Balfour notched his 23rd save and snapped Dennis Eckersley's franchise record with his 41st consecutive save dating to last year.

Jed Lowrie had a pair of hits and scored a run and Derek Norris drew a bases-loaded walk for the Athletics, who improved to 10-0 all-time against Pittsburgh. Josh Donaldson had a sacrifice fly for his team-high 58th RBI.

Jeff Locke (8-2) had his eight-game winning streak snapped, allowing two runs on three hits over seven innings to lose for the first time since his season debut on April 7. The loss also halted an eight-game interleague winning streak for the Pirates and dropped them a half-game behind St. Louis in the National League Central.

Oakland went ahead in the fourth when Lowrie doubled and scored on Donaldson's sacrifice fly, and made it 2-0 in the seventh on Norris' bases-loaded walk. The Pirates got a run back in the bottom of the inning when Clint Barmes doubled and scored on Jose Tabata's infield single, but center fielder Coco Crisp prevented more damage with a diving catch of Andrew McCutchen's lineout.

GAME NOTEBOOK: Pirates LF Starling Marte went 0-for-5 and had his 12-game hitting streak snapped. ... The Athletics called up former first-round pick Grant Green from Triple-A Sacramento and designated INF Adam Rosales for assignment. Green started at second base and went 0-for-3 in his major-league debut. ... Locke allowed two earned runs or fewer for the ninth time in his last 10 starts while Colon registered his 11th straight start of at least six innings with three runs or fewer - the second-longest streak in team history since 1920.