Clay Buchholz shut down the Orioles over six innings and Jason Bay hit his 34th homer as Boston topped the Birds 3-1 Friday night to start a three-game series.
The O's fall to 2-3 on this seven-game homestand.
Buchholz, now 6-3, 3.49, gave up just five hits and one run, throwing 95 pitches. Over the last 11 games, Red Sox starting pitchers have worked to an ERA of 1.77.
Jeremy Guthrie took the loss, allowing nine hits and three runs over 5 2/3. Guthrie, 10-15, leads the AL in losses despite an ERA of 2.82 over his last six starts.
Casey Kotchman's RBI single gave Boston a 1-0 lead in the second. In the bottom of the inning, Luke Scott's solo homer, a 383-foot shot to right center, tied the game, 2-2. It was his 23rd homer.
Jason Bay led off the 4th with a solo homer for a 2-1 lead. An inning later, Bay left the game due to flu-like symptoms. A Jacoby Ellsbury RBI single in the 6th gave Boston the 3-1 edge.
The Red Sox improve to 14-2 on the year vs. the Orioles with six consecutive wins. The Sox are 21-3 in the last 24 games between the teams.
The O's have just 14 hits the past three games.
Boston has won eight of its last nine games and is 25-11 since August 10th.