OAKLAND, Calif.

Matt Thornton didn’t have a problem with the pitch he served up for a game-winning hit in his Boston debut.

It was the two walks he allowed earlier in the inning that really irked the left-hander.

Two days after being acquired from Chicago, Thornton’s command problems were the difference on a day when Red Sox rookie Brandon Workman had a stellar outing in his first major league start.

Josh Donaldson blooped an RBI single off Thornton (0-4) with two outs in the 11th inning and the Oakland Athletics beat Boston 3-2 to hand the Red Sox their second straight loss following a fourgame winning streak.

“Any time you walk guys like that you’re putting yourself behind the eight-ball and you’re right in trouble from the get-go,” Thornton said. “I got myself in a jam then made a pretty good pitch to Josh. But that hit doesn’t matter if I don’t walk guys. Walking guys late in a game will kill you every time.”

It was a tough day all around for the Red Sox.

Left fielder Jonny Gomes struck out three times and was ejected in the ninth inning for arguing with home plate umpire Todd Tichenor. Manager John Farrell managed to convince another umpire to overturn a call in the 10th inning following a botched throw by shortstop Jose Iglesias, only to have it changed again.

The Red Sox also loaded the bases with two outs without benefit of a hit in the 11th before winning pitcher Ryan Cook (2-2) caught Brock Holt looking at a called third strike.

Boston completed a 5-5 road trip but still heads into the All-Star break with plenty of momentum, not to mention a major league-leading 58 wins.

The Red Sox also have some more flexibility to their rotation following an impressive outing by Brandon Workman in his first major league start.

Workman gave up only two hits and one walk in 6.1 innings to become the first Red Sox pitcher to allow three or fewer base runners in his first big league start since 1934.

Workman took a no-hit bid into the seventh inning, losing it when Coco Crisp beat out a leadoff infield single. He became the third rookie in four days to pitch no-hit ball into the sixth inning of his first big league start — Houston’s Jarred Cosart and Cleveland’s Danny Salazar also did it in their major league debuts.

Dustin Pedroia’s RBI single in the sixth off Oakland starter Bartolo Colon put the Red Sox up 1-0. Holt later singled in Mark Carp, who doubled leading off the seventh.

It wasn’t enough for the Red Sox, who have not won a series in Oakland since July 2006.

Donaldson hit a two-run homer off Workman to tie it in the seventh, then singled in the game-winner with two outs in the 11th.

Colon gave up two runs and eight hits over 6.1 innings. He did not walk a batter and struck out four. The Oakland pitcher will not play in the All-Star game after starting Sunday.

Notes — Red Sox pitcher Drake Britton was called up from Triple-A Pawtucket and outfielder Jackie Bradley Jr. was optioned to Pawtucket. … Boston pitcher Clay Buchholz (9-0, 1.71) threw a second bullpen session before the game and will likely throw one more on Tuesday before making a rehab start. … Red Sox shortstop Stephen Drew will play two more games in the minors before rejoining the big league club Saturday when the Yankees visit Fenway Park. … Gomes was ejected for the third time in his career and first since June 5, 2008.