Orioles 8, Red Sox 2: Mark Reynolds capped a seven-run third inning with a three-run homer and Jason Hammel tossed 6 2/3 strong innings as Baltimore posted its sixth win in seven games.
Adam Jones also homered for the Orioles, who improved to 4-1 on their six-game road trip.
Baltimore took a 1-0 lead in the second when Chris Davis hit a two-out single, went to third on Wilson Betemit's base hit and scored on a passed ball by Jarrod Saltalamacchia. An inning later, the Orioles erupted for seven runs to put away the game.
Nick Markakis began the uprising with an RBI single and Jones followed with a two-run blast for a 4-0 advantage. Betemit chased Aaron Cook with a run-scoring single three batters later, and Reynolds greeted Clayton Mortensen with a three-run shot that completed the rally.
Hammel (4-1) allowed two runs and four hits with a walk, striking out eight. The 29-year-old has yielded two runs or less in each of his six starts this season.
Cook (0-1) was tagged for seven runs - six earned - and eight hits in just 2 2/3 innings in his Red Sox debut.
Adrian Gonzalez collected three hits and scored a run for Boston, which has started 4-9 at home for the first time since 1984.
GAME NOTEBOOK: Reynolds has homered in each of his last two games after failing to go deep in his first 20 contests. ... The Red Sox have lost nine of their last 10 at Fenway Park. ... The win was Hammel's first in four career starts against Boston. ... Cook was spiked by Davis while covering the plate on the passed ball in the second inning and suffered a nasty gash on his leg but remained in the game.