HOUSTON -- The first major league win eluded Astros rookie right-hander Vince Velasquez on a couple of occasions when he was worthy, making Tuesday night a prime example of delayed gratification.

Velasquez survived a rocky third inning en route to his milestone as the Houston Astros beat the Boston Red Sox 8-3 at Minute Maid Park.

Velasquez (1-1) worked six innings, allowing seven hits and three runs while recording seven strikeouts. After running into trouble in the third, he rebounded to allow just two baserunners over his final three innings. He was making his seventh start this season and his first in two weeks after a hiatus with Double-A Corpus Christi to lower his innings count.

"I think he picked his tempo up a little bit," Astros manager A.J. Hinch said. "That was something that he worked on in Double-A with (Corpus Christi pitching coach Doug) Brocail, the rhythm of his delivery to speed his tempo up a little bit. That helped him."

The Astros (52-43) erased a 3-1 deficit with a four-run fifth inning and added insurance in the sixth with a two-run, opposite-field home run from designated hitter Chris Carter, his 16th on the season.

Astros second baseman Jose Altuve reached base in four of five plate appearances, scoring twice and recording an RBI single in the eighth. Carter finished 2-for-3 and scored two runs.

The Red Sox (42-52) dropped their sixth consecutive game, with left-hander Brian Johnson (0-1) taking the loss in his major league debut.

"I felt (nervous) the first hitter, yeah," Johnson said. "But then after that, got into competitive mode and it was fun."

Johnson retired eight consecutive batters after issuing consecutive one-out walks in the second inning. He dodged a bit of a mess in the first, allowing just one run before inducing an inning-ending double play off the bat of Astros left fielder Evan Gattis.

However, four batters into the fifth inning, Johnson was gone, chased by his fourth walk, this one to Altuve. Houston had already pulled even at 3-3 when center fielder Jake Marisnick turned a steal attempted into a two-base error, scoring behind Carter when the throw of Red Sox catcher Ryan Hanigan deflected off Marisnick and rolled into left-center field.

Johnson lasted just 4 1/3 innings, allowing four runs on three hits and four walks with three strikeouts. The Astros tacked on two more runs in the fifth, greeting Red Sox right-hander Justin Masterson with a double by shortstop Carlos Correa and a run-scoring groundout from Gattis.

"I thought he threw a number of good curveballs, particularly in the second through the fourth inning of work," Boston manager John Farrell said of Johnson. "He started to settle into, I thought, a decent rhythm. I would imagine there were some nerves he was dealing with in that first inning. He was able to get out of that first-and-third situation with one run allowed."

Velasquez faced his own bit of adversity in the third when a check swing from Red Sox center fielder Mookie Betts fortuitously turned into a two-run double. Betts later scored when shortstop Xander Bogaerts singled to center, lifting Boston to a 3-1 lead. However, Velasquez struck out left fielder Hanley Ramirez to end the threat and ignite the charge to his first win.

"I got a lot of text messages from friends and family at home. They're all excited," Velasquez said. "(My teammates) showered me three times. I guess I'll need an ice bath after a while, but I'll do that after tomorrow. It was a good little celebration and just a great team win overall."

NOTES: To make room on the roster for RHP Vince Velasquez, the Astros designated LHP Joe Thatcher for assignment. Thatcher (1-3, 3.79 ERA) proved to be a luxury as a second left-hander in the bullpen, and his recent struggles (0-1 with a 21.60 ERA in seven games this month) made him expendable. ... After a rare rainout in Anaheim forced the Red Sox to play a doubleheader against the Angels on Monday, Boston tweaked its rotation and pushed back LHP Wade Miley, who will start the series finale at Houston on Thursday. RHP Joe Kelly will be recalled from Triple-A Pawtucket to start Wednesday night. ... Astros INF Jed Lowrie will begin a rehab assignment Wednesday night with Double-A Corpus Christi. Lowrie, who will start at third base but should also see time at shortstop during his rehab stint, has been on the disabled list since April 28 after surgery to repair a torn ligament in his right thumb.