Buchholz, Red Sox blank Astros in HoustonBoston right-hander struck out 12 in Sunday's 11-0 victory
But he was far from the only Astro to struggle in a lopsided 11-0 loss to the Boston Red Sox.
Peacock couldn't locate his pitches, forcing Houston to use five relievers to finish the game.
Clay Buchholz allowed three hits and struck out a career-high 12 in his fifth career shutout to lead the Red Sox to their fourth victory in five games heading into the All-Star break.
Brock Holt had a career-best five hits, including a leadoff homer, to pace the Boston offense.
Holt hit Boston's first leadoff homer of this season. Dustin Pedroia singled before David Ortiz drew a walk. Astros manager Bo Porter had seen enough and pulled Peacock after he plunked Daniel Nava on his 27th pitch.
Porter wanted to make a change before things got out of hand.
''It's not like he had command of the strike zone,'' Porter said. ''At that point, you say to yourself, 'Are you going to wait until it is 4 or 5 to nothing or are you going to try to give us a chance?' I felt like we had a better chance to get another guy in there at that point.''
The decision didn't sit well with Peacock.
''I really don't know why I came out,'' he said. ''I felt fine. I just had a little control issues there. I didn't get a chance to talk, but I don't know.''
All of the hits Buchholz (4-5) allowed were singles, and he didn't walk a batter in his first shutout since June 2, 2013, against the Yankees.
Chris Carter extended his career-high hitting streak to nine games with a single with one out in the fourth. Buchholz sailed through the rest of the game, retiring his last 17 batters.
''He had it all working,'' Porter said of Buchholz. ''You look at pinpoint command of his fastball, he threw his curveball anytime he wanted for strikes, mixed in his changeup and did a tremendous job.''
Major league hits leader Jose Altuve went 0 for 4, rookie Jon Singleton extended his slump to 12 at-bats with an 0 for 3 day, and both players had an error.
Holt, who played at Rice, launched a 92 mph fastball from Peacock (3-6) into the seats in right field to give Boston an early lead.
Rookie Christian Vazquez had two hits and two RBIs to help the Red Sox score a season-high 11 runs.
Xander Bogaerts walked to start the second and advanced to second on a passed ball. Stephen Drew's single sent Bogaerts to third and he scored when Vazquez grounded into a double play to make it 2-0.
Holt and Pedroia then hit back-to-back singles, but Anthony Bass retired Ortiz to limit the damage.
Mike Napoli singled with no outs in the third before Nava reached on an error by first baseman Jon Singleton. An RBI single to center field by Jackie Bradley Jr. pushed the lead to 3-0 before a sacrifice fly by Bogaerts scored another run.
The bases were loaded with two outs in the fifth when Josh Zeid replaced Darin Downs and was greeted with an RBI single by Vazquez. A throwing error by Altuve on the play allowed a second run to score and extend the lead to 6-0.
An error and a single by Drew left runners at the corners with one out in the seventh. The Red Sox made it 7-0 on a sacrifice fly by Vazquez. Holt singled before Pedroia walked, and Ortiz drew a bases loaded walk to push the lead to eight runs.
Boston tacked on three more in the ninth inning.
NOTES: Carter, who is normally the designated hitter, played left field for the first time since last season. That allowed George Springer to be the designated hitter because of soreness in his right knee. ... The Astros' 40 wins at the break are the most they have had in the first half since winning 44 in 2009.