(SportsNetwork.com) - The Boston Red Sox haven't won three in a row since early April and will shoot for that mark Tuesday in the second installment of a three-game series against the Oakland Athletics.

The Red Sox opened this Bay Area series with Monday's 5-4 win in 11 innings and third baseman Pablo Sandoval was back on the west coast. Sandoval, a former hero for the San Francisco Giants, felt right at home and belted a solo homer in the top of the 11th inning.

Matt Barnes, not the Los Angeles Clippers forward, threw two scoreless innings of relief and set the Athletics down in order in the bottom of the 11th inning to pick up his first career win.

"Pablo had a big home run that put us ahead," Barnes said. "That first inning I was trying to keep it where it was and the second inning I was just trying to get those three outs and get the team a win."

Mookie Betts had two hits and two RBI, David Ortiz went 2-for-5 and drove in a run and both Xander Bogaerts and Blake Swihart posted two hits for the Red Sox, who have won two straight and are 2-2 on a 10-game trek. It was Boston's third win over the last 10 contests.

Rick Porcello started for the Red Sox and gave up three runs in five innings.

Red Sox outfielder Shane Victorino was activated off the disabled list on Monday night and went 0-for-4.

Justin Masterson draws the start for the Red Sox Tuesday and is 2-1 with a 5.18 earned run average through six outings. Masterson is in his first season with Boston and is 0-1 in his previous three starts -- all losses. He allowed four runs in a season-low 4 1/3 innings of a 5-3 loss to Tampa Bay on Wednesday.

Masterson has faced the Athletics 14 times (10 starts) in his career and is 2-7 with a 6.61 ERA.

Oakland is mired in a six-game slide and is 10 games under .500 (12-22) for the first time since finishing the 2011 season 14 under (74-88).

Angel Castro served up Sandoval's home run and Scott Kazmir threw the first six innings, charged with two runs and four hits in six innings.

Billy Butler recorded three hits, an RBI and a run scored, while Stephen Vogt drove in two runs and both Billy Burns and Josh Reddick added two hits with an RBI for the Athletics, who have lost by one run four times in the last five games.

"It's been the same story and it's tough to explain," A's manager Bob Melvin said of the close losses. "It's been a little surreal."

Drew Pomeranz looks to play stopper for the A's Tuesday and is only 1-3 with a 5.12 earned run average in six starts. The A's have lost his last five appearances and the left-hander is 0-3 in that time. In a 6-5 loss at Minnesota on Thursday, Pomeranz was hit for six runs (4 earned) in 4 1/3 innings.

Pomeranz has faced Boston twice before in relief and has a 2.70 ERA over 3 1/3 innings of work.

Boston and Oakland are meeting for the first time this season. The A's went 4-3 against the Red Sox in 2014.