Red Sox 7, Astros 2: Red-hot David Ortiz had three hits and hit his first homer of the season while Clay Buchholz struck out 10 and became the first five-game winner in baseball as host Boston won the opener of the four-game series.

Buchholz (5-0) allowed two runs and six hits, and retired 11 straight batters before Jose Altuve ended his night with a two-out single in the eighth. Jarrod Saltalamacchia and Ortiz had two RBIs apiece - one each in a four-run first inning - for first-place Boston, which is 11-0 when scoring first.

Philip Humber (0-5) allowed seven runs and 10 hits in 4 2/3 innings as the Astros began a seven-game road trip, which will also take them to Yankee Stadium, with their sixth straight loss away from home. Fernando Martinez had a career-high three hits for Houston.

Dustin Pedroia delivered an RBI single with one out in the first, stole second uncontested and scored on Ortiz's blistering line-drive to right field. With two outs, Mike Carp's broken-bat hit eluded first baseman Carlos Pena and went for an RBI double and Saltalamacchia followed with a line shot up the middle to plate Carp and make it 4-0.

Ortiz gave the Red Sox a 5-2 lead when he led off the third inning with a blast into the center field bleachers. Boston added two runs in the fifth as Saltalamacchia delivered a two-out single and Will Middlebrooks followed with a run-scoring double.

GAME NOTEBOOK: Ortiz, who missed the first 15 games of the season because of heel injuries and was rested in two others, is 11-for-20 with five RBIs in five contests. ... Boston RHP Daniel Bard, who was recalled from Double-A Portland on Wednesday, pitched a scoreless ninth inning in his season debut and 200th career relief appearance. ... Humber is 4-10 with a 7.54 ERA in 29 games since throwing a perfect game at Seattle on April 21, 2012. He has allowed 15 runs in his last two starts covering five innings.