Batting with runners in scoring position has been a challenge for the Red Sox for most of the season. They entered Friday’s series opener against the Athletics hitting just .223 in such situations. Through the first five innings Friday, they were just 1-for-7 with runners in scoring position, as they clung to a one-run lead against Oakland.

Dustin Pedroia took care of that, though, in the sixth inning, launching an 0-and-2 slider from reliever Ryan Cook into the monster seats in left field with the bases loaded for his second career grand slam, as the Sox beat the A’s 7-1.

It was the 100th home run of his career, giving him 503 career RBI. It was just his first home run of the season, coming 164 at-bats since his last on Sept. 17, 2013.

Pedroia joins Carl Yastrzemski as the only players in Sox history with at least 100 home runs, 500 RBI, and 100 stolen bases.

Clay Buchholz earned the win, improving to 2-2 lowering his ERA from 6.66 to 5.63. He went 6 1/3 innings, giving up one run on three hits and three walks with five strikeouts.

The Sox knocked A’s starter Dan Straily out after just 4 1/3 innings, forcing him to throw 82 pitches. Straily took the loss, giving up two runs on four hits with a three walks and three strikeouts.

The Sox got two runs in the second as Grady Sizemore led off with a double, scoring on A.J. Pierzynski’s one-out single. Jackie Bradley’s two-out double scored Pierzynski.

The A’s got a run in the third when John Jaso led off with a triple to deep center field, scoring on wild pitch from Buchholz with two outs.

In the sixth, the Sox batted around as they went through three A’s relievers, starting with right-hander Dan Otero, who had never faced the Sox before. He opened the inning giving up consecutive singles to Bogaerts and Pierzynski before striking out Middlebrooks, and walking Bradley.

That ended Otero’s outing, bringing in Ryan Cook, who had not allowed a run in six previous Fenway appearances. He had Pedroia down, 0-and-2, but Pedroia blasted the third straight slider into the monster seats in left field, giving the Sox a 6-1 lead.

The home run was challenged by A’s manager Bob Melvin, but was upheld after a video review.

Cook then struck out Shane Victorino before giving up a double to David Ortiz and a walk to Napoli, ending his outing. Drew Pomeranz entered, getting Grady Sizemore to fly out, ending the inning.