The Pirates' No. 8 prospect allowed one run on one hit over seven innings Wednesday as the Triple-A Indianapolis Indians shut down the Louisville Bats, 6-1.
Locke (7-4) fanned six, walked three and threw 59 of 99 pitches for strikes. The only hit he allowed came in the sixth, when Kris Negron led off with a triple. Cody Puckett followed with a sacrifice fly, snapping Locke's string of 11 2/3 scoreless innings.
"I was working off my last start, where I was commanding my fastball more," he said. "I was working it to both sides of the plate. It's a lineup I've faced a bunch of times. With guys you've faced a lot, you have to stay sharp and make adjustments because they're doing the same. I had some great plays behind me and it was a great team effort."
Locke helped the Indians extend their winning streak to eight games. They have a 12-game lead over second-place Columbus in the International League's West Division.
"It's a lot of fun," Locke said. "Everyone's been on a team where things didn't click, and early in the year we had some struggles. Right now, we're hot, we're playing real well. It's more than a pleasure to come to the ballpark. It's not something we can take for granted; we know we have to play hard, and so far everyone has been tremendous about it."
Locke lowered his ERA to 2.92 ERA, which ranks seventh in the league. He's also sixth with 84 strikeouts and has been remarkably consistent, having not allowed more than three earned runs in a start since May 10.
"You see some of the guys on the pitching staff I'm around, Rudy Owens and Justin Wilson, they lead off the MiLB.com site every week," Locke said. "We work hard, we compete with each other, everyone wants to have a sharp outing and everyone wants to follow up each other. We have a lot of good guys on the staff and you feel good when you come to the park.
"I've had this fantastic defense behind me and fantastic catchers behind the plate. Personally, I just want to continue what I'm doing right now and stay consistent. You can't afford to have those days where nothing's there. You have to compete when you don't have your best stuff and get guys out when you don't have a good fastball and your changeup command isn't there. "
Bryan Morris allowed one hit and struck out two in the eighth and Evan Meek tossed a hitless ninth for the Indians.
Starling Marte, Pittsburgh's No. 3 prospect, tripled in the bottom of the first to extend his hitting streak to 10 games.
"There is no one in the world that can run from the wall to second base and vice-versa better," Locke said, "He's a guy that puts forth good at-bats every time."
Jeff Clement homered twice and scored three runs, while Chase d'Arnaud slugged a two-run shot for Indianapolis.