Josh Willingham hit a go-ahead three-run homer in the fifth inning, Daric Barton added an insurance run in the sixth and the Oakland Athletics beat the Baltimore Orioles 6-4 on Sunday to complete their first three-game sweep this season.
Kevin Kouzmanoff added two hits for Oakland, which extended its longest winning streak this season to four games. The A's also continued their home dominance of the Orioles with their 12th win in 13 tries at the Coliseum.
Oakland got a boost from two-time All-Star closer Andrew Bailey, who made his season debut after being sidelined with a strained right forearm. He pitched a scoreless seventh.
Vladimir Guerrero singled in the eighth to extend his hitting streak to 14 games, but the Orioles couldn't score against four Oakland relievers and dropped their third straight on the road after a five-game winning streak at home.
Guillermo Moscoso (2-0) gave up five hits with two walks to earn his second straight win after being called up from the minors on May 24 to replace injured starter Tyson Ross.
Willingham's second homer in three days capped a four-run fifth and gave the A's a 5-4 lead. It's only the fourth three-run shot of the season for Oakland, which has the third-fewest home runs (30) in the majors.
Baltimore led 4-1 after loading the bases against Moscoso in the top of the inning then scoring four runs with only one hit.
Felix Pie had an RBI single that A's center fielder Coco Crisp appeared to make a diving catch on before the ball popped out of his glove after hitting the ground. Nolan Reimold, pushed into action when center fielder Adam Jones left with a sore shoulder, then drew a bases-loaded walk and Nick Markakis and Guerrero added run-scoring groundouts.
The loss of Jones left the Orioles without their leading run producer.
That's significant for a team that has struggled to score on this road trip. After getting four runs against Moscoso, Baltimore managed only two baserunners over the final four innings.
It was a frustrating weekend all around for the Orioles, who were held to 19 hits and grounded into seven double plays during the series.
The A's got a lift from Bailey, who had been on the DL since March 30. The 2009 AL Rookie of the Year retired all three batters he faced as Oakland tries to ease him back into the mix.
"He's had enough rehab assignments and he feels like he's ready," Oakland manager Bob Geren said before the game. "It makes a good bullpen even better."
Oakland gave Bailey a 6-4 lead to work with after chasing Baltimore starter Zach Britton in the sixth. Barton hit a sacrifice fly to drive in Mark Ellis after the Orioles intentionally walked Crisp to load the bases.
Britton (5-3) was tagged for career highs of six runs and 10 hits. The left-hander, who was attempting to tie Jake Arrieta for the team lead in wins, walked three and struck out three.
Willingham singled to drive in Barton in the first with the A's first run. In 16 career games against the Orioles, Willingham is batting .400 with four home runs and 12 RBIs.
NOTES: Baltimore sent struggling RHP Brad Bergesen to Triple-A Norfolk and called up LHP Pedro Viola from Double-A Bowie. Bergesen (1-6) took the loss in Saturday's game. ... To make room for Bailey the A's optioned LHP Bobby Cramer to Triple-A Sacramento. Cramer was called up Friday when Oakland traded David Purcey to Detroit but did not pitch against Baltimore.