Through the initial three innings Tuesday, the Astros had only two hits and one run.

Normally, the lack of meaningful contact and real production would have been major problems and a rebuilding club would have gradually moved closer toward its 46th defeat in 72 games.

But Jordan Lyles was on the mound. The highly confident 22-year-old who’s quietly become one of the most promising young arms in Major League Baseball during the last two months.

A 6-4, 215-pound righthander who’s suddenly turned from a spring-training roster cut into the best pitcher wearing an Astros uniform not named Bud Norris.

Entering Tuesday, Lyles had allowed just seven earned runs during his last 372⁄3 innings, and his 1.67 ERA in the six-start span was third-best in the American League. Following the Astros’ 10-1 victory over the Brewers on Tuesday at Minute Maid Park before an announced crowd of 13,330, Lyles’ promise was clearer, his numbers were sharper and the improving Astros (27-45) are a step closer toward knowing the third-year pitcher is turning into a long-term top-of-the-rotation starter.

“He’s growing up right in front of our eyes,” manager Bo Porter said. “A lot of times, you kind of take a step back and re-evaluate where you are at. That step back was very good for him, and he’s now taken multiple steps forward. And we’re reaping the benefits of a guy who’s made right.”

Lyles powered through seven sharp innings, giving up seven hits but scattering them and holding Milwaukee to one run on 100 pitches (73 strikes). He struck out five, walked none and improved to 4-1 with a 3.22 ERA this season.

Lyles’ fastball hit 94 mph while he alternated two-seamers with four-seamers. A looping curve was offset by a tailing slider and a hard changeup. Mix in constant Milwaukee confusion in the box, a game-changing three-run homer by Carlos Pena during the fifth inning and Matt Dominguez’s first career grand slam in the seventh, and it was Lyles’ seventh consecutive outing in which he allowed two runs or less, and the Astros’ fifth win in six games.

“It’s easy (to stay grounded) because I know where I was last year and two years ago. For me to just throw away what happened the past year, it’s not right,” Lyles said. “I know where I came from and I’m just trying to take it one day at a time right now.”

Brewers hitters often were off balance and barely able to connect during the initial two frames. Lyles stretched his scoreless-inning streak to 12, while Logan Schafer swung through a 1-1 87 mph slider that left Milwaukee’s No. 6 hitter tightly coiled, then picking his helmet up off the dirt.