BOSTON -- Mired in a slump, Dustin Pedroia had an MRI on his right knee to see whether that might be causing his problem.
The test was negative.
The results were positive.
"I think when he had his knee checked out, that was good for him. He knew he wasn't hurting himself," Red Sox manager Terry Francona said after Pedroia homered to help Boston beat the Arizona Diamondbacks 6-2 on Wednesday night. "He's just a good player. You wind him up and let him go play. He'll produce."
Rodrigo Lopez (2-6) lost his fourth straight decision, giving up Marco Scutaro's single to lead off the Red Sox first before Pedroia hit a line drive over the Green Monster for his ninth homer of the season. Pedroia also singled and scored in the third inning -- his fifth multihit night in his past six games.
"I've hit my whole life," he said. "It's not going to stop."
Pedroia began slumping in mid-May, though, and his average dropped from .305 to .248. He said Thursday that his knee had been bothering him, and he had an MRI.
The test didn't show any damage, and the news gave Pedroia the confidence to return to his all-out style of play.
"I'm feeling better. That's the biggest thing," he said. "It definitely helped me."
Lester gave up Justin Upton's two-run homer in the second inning and then just two more singles. He struck out seven -- giving him a share of the AL lead for strikeouts with 96 -- but also walked three and hit two batters.
"It's kind of night and day from inning to inning and batter to batter sometimes," he said. "Obviously, your objective is to win the game, and we did that tonight. But there are still things that need to be refined."
Lopez allowed six runs, 10 hits and two walks in seven innings and struck out three. Sam Demel, acquired Tuesday in a trade with Oakland, made his major league debut in relief and pitched a perfect eighth.
The Diamondbacks haven't won on the road since May 17 -- a full month.
"Any time you lose a game, it's tough," manager A.J. Hinch said. "We certainly haven't won a game in our gray uniforms in a long time."
The Fenway Park crowd broke into the now-obligatory chant of "Beat L.A.!" in support of the Celtics, who will play Game 7 of the NBA Finals against the Lakers on Thursday night. More surprising was the sound of a vuvuzela -- one of the buzzing horns made famous from the World Cup -- coming from the stands.
The Red Sox scored two in the third, but Chris Young avoided more damage when he leaped against the center-field wall to take an extra-base hit away from Victor Martinez. Young came down with his hat crooked and apparently in a bit of pain, but he stayed in the game.
The next batter, J.D. Drew, hit a line drive to Young's right, but he couldn't get to it and played it off the Green Monster. Pedroia scored, then David Ortiz scored on Adrian Beltre's infield hit to make it 4-2.
Youkilis added a two-run homer in the seventh. It was his 13th homer.
Lester is 8-0 with a 2.01 ERA in 11 starts since opening the season 0-2.
The Red Sox announced that LHP Felix Doubront will start on Friday in place of Daisuke Matsuzaka, who is on the disabled list with a forearm strain. ... The Red Sox signed 10 draft choices, including first-round selection INF Kolbrin Vitek and second pick OF Bryce Brentz. Both players were assigned to the Class A Lowell Spinners. Also agreeing to terms with the club were right-handed pitchers Garrett Rau, Keith Couch and Michael Gleason; shortstops Nick Robinson and James Kang; outfielder Luke Yoder, catcher Jayson Hernandez and first baseman Trygg Larsson-Danforth. ... Scutaro was back in the lineup at shortstop after he missed a game because of a sore neck.