The Mets' No. 2 prospect recorded a career-high 11 strikeouts while allowing three runs on four hits over six innings as the Triple-A Buffalo Bisons beat the Braves, 5-3.
Harvey (4-1) made his way through a rough first inning, allowing solo homers to Stefan Gartrell and Ernesto Mejia that staked Gwinnett to a 2-0 lead. The 2010 first-round pick recovered and put up zeros in the second, third and fourth before allowing an RBI double to Drew Sutton in the fifth.
"I threw two pitches that caught too much of the plate, but after that, I settled in," said Harvey, who threw 24 pitches in the opening frame. "After that first inning, I was able to get ahead with off-speed stuff. I was able to get my changeups in there and I was just able to trust my stuff and attack the zone and work ahead."
Harvey, whose third and most recent 10-strikeout game came on April 20 against Syracuse, fanned at least two batters in every inning except the third. He remained unbeaten since his Triple-A debut on April 5.
"After that first, I wanted to limit the damage," Harvey said. "I really wanted a quality start and keep the team in the game, and I did that. I knew that I was going to have to bounce back and attack the strike zone."
The 23-year-old right-hander surrendered 11 earned runs in his first three starts of the season. Since then, he's posted a 3.09 ERA while allowing 27 hits over 35 innings. Harvey credited a tweak in his delivery that he came up with working with pitching coach Mark Brewer.
"I'm keeping the motion as easy as possible and getting that extra aggression out at the end of the motion and keeping the ball down," the University of North Carolina product said. "My motion is kind of slow and we were wondering why I was yanking balls. And in batting practice, we worked on keeping things nice and calm.
"Brewer's been a big help and credit goes to what we do in between starts and what we do in the bullpen."
Harvey ranks fifth in the International League with 49 strikeouts and has a 4.31 ERA in nine starts. He's won four straight decisions and has limited opponents to a .255 batting average.
Valentino Pascucci slugged his eighth and ninth homers and drove in four runs for the Bisons.
"That guy, he's got some crazy pop," Harvey said. "Once he gets going, his homers come in bunches. That was the biggest help, him having four RBIs and two monster bombs. When he connects, you never know how far it's going to go."
Dylan Owen allowed three hits over the final three frames to record his first save of the season.