BOSTON (AP) -- Baltimore manager Buck Showalter decided it was time to let Wei-Yin Chen handle things on his own a little more.
The rookie left-hander passed the test.
Chen scattered seven hits over seven innings and the Orioles set a franchise record with their seventh straight victory in Boston, beating the Red Sox 2-1 on Wednesday night.
Chen's most important inning was the seventh, when Boston had runners on second and third after a pair of singles and a sacrifice. He struck out Marlon Byrd and got Mike Aviles to pop up to short right, escaping the jam.
"He'd pitched too effectively not to let him decide his own fate," Showalter said.
Chen, the first Taiwanese-born player in Orioles history, is slowly building a nice season. He understood the faith his manager showed.
"I really appreciate that Buck trusted me," Chen said through a translator. "That's the key point."
And the Orioles, who moved into sole possession of first place in the AL East, made another point that they're proving to be trouble for the Red Sox again this season.
The Orioles, who knocked Boston out of the postseason on the final night of the regular season last year, have won 12 of the past 15 meetings. They are 5-0 at Fenway Park this season.
Endy Chavez , who had three hits in a series-opening win Tuesday, drove in the go-ahead run with a grounder in the sixth. Boston has lost three straight for the first time since early May.
"Everybody's doing a little part for the team," Chavez said. "As a team, we are playing pretty good even though we have a lot of injuries. We're playing good. We're focused and we're fighting and all together. That's very important."
Chen (5-2) was coming off the worst start of his first major league season, when he allowed five first-inning runs Friday in a loss to Tampa Bay. This time he struck out four, didn't walk anyone and stranded six runners.
Josh Beckett (4-6) was the tough-luck loser, allowing two runs, five hits and striking out five in eight innings. It was the fifth consecutive start he's pitched at least seven innings.
"I learned a lot from him tonight," Chen said of going against Beckett. "I haven't had a win in a long time. It was a relief to me."
Chen went 0-2 with a no-decision in his previous three starts.
Aviles thought Boston's best shot came in the seventh.
"Yeah, that's exactly what it came down to. Their pitchers basically outpitched our hitters," he said. "It was a great-pitched ballgame all around. Josh pitched unbelievably well and he definitely deserved to win and unfortunately we weren't able to back him up with the bats."
Beckett declined to talk to reporters.
Jim Johnson , who had his first blown save of the season Tuesday after converting 25 straight chances dating to last year, got three outs for his 18th save. The first batter he retired was Jarrod Saltalamacchia , who hit a tying, two-run homer one night earlier.
Trailing 1-0 and with just a single in the first five innings, the Orioles opened the sixth with three consecutive hits and took the lead with two runs. Robert Andino had an RBI single after Wilson Betemit and Ryan Flaherty singled. Chavez's fielder's choice made it 2-1.
The Red Sox grabbed a 1-0 lead in the third when Darnell McDonald doubled off the Green Monster, advanced on Marlon Byrd 's single and scored on Mike Aviles ' sacrifice fly.
Chen allowed hits in every inning except the first, but kept the damage to a minimum.
With help from third baseman Will Middlebrooks , who made a diving grab of Mark Reynolds ' second-inning liner, Beckett retired the first nine batters on 29 pitches, fanning three.
Beckett faced the minimum and held the Orioles to one runner through the first five innings - Chavez's single leading off the fourth. Chavez was erased when J.J. Hardy bounced into a double play.
NOTES: The Orioles signed 49-year-old LHP Jamie Moyer to a minor league deal and assigned him to Triple-A Norfolk. He is expected to start Saturday against Buffalo. Showalter said Moyer will get "two or three starts down there and we'll see what happens." Moyer became the oldest pitcher to win as a starter when he earned a victory with Colorado in April. ... Red Sox manager Bobby Valentine said RHP Daisuke Matsuzaka will start Saturday against Washington, one day before the one-year anniversary of his Tommy John surgery. Matsuzaka made eight rehab starts and is taking the spot of Daniel Bard , sent to Triple-A Pawtucket on Tuesday. Bard, a converted reliever, is 5-6 with a 5.24 ERA. ... The Orioles selected Cal Ripken Jr.'s son, Ryan, in the 20th round of the draft. "That was pretty cool," Showalter said. "This kid's got a chance to be a player. He's an outstanding prospect." The 6-foot-6 Ryan Ripken played at the Gilmon School in Baltimore. ... Showalter also said he heard 2B Brian Roberts , attempting to come back from a concussion sustained more than a year ago, "looked good. He's moving around and playing good defense." Roberts is playing in the minors.