The 23-year-old right-hander earned more praise from interim manager Tim Bogar, who has watched Martinez evolve from a novice to a dependable member of the rotation in a matter of months.
"I thought this could have been his best performance in the fact that I liked how he handled himself on the mound," Bogar said. "Early in the season, you could see him let the game speed up on him and tonight he didn't allow that to happen. He had a couple of tough situations that he got out of tonight and it just shows his maturity."
Over his previous four starts, Martinez had a 2.74 ERA (seven earned runs in 23 innings) despite hovering around the 5.00 mark for the season. He was as sharp as he has been lately against the Astros, striking out five and scattering five hits while walking none.
"I feel pretty good about that one," said Martinez, who got his first win at Globe Life Park. "I felt good, I was commanding my fastball, I had real good feel for my changeup ... This time, I was just attacking them, getting strike one, strike two and going after them."
Martinez credited some of his aggressiveness to a recent visit with Hall of Famer Greg Maddux, who serves a special assistant for the Rangers. Martinez said Maddux told him not to worry about throwing his out pitch early in the count to create early contact, and just focus on getting ahead.
Martinez said he has learned "a tremendous amount" this season.
"The list goes on and on," he said.
Thanks to Martinez's outing and solid relief work from fellow rookie Spencer Patton and veteran Neal Cotts, the Rangers didn't need much offense. All it took was a two-run fourth inning courtesy of Robinson Chirinos' solo homer and Daniel Robertson's RBI single.
Cotts yielded a run in the ninth on Matt Dominguez's sacrifice fly, which scored Dexter Fowler, who drew a one-out walk before Jake Marisnick's double to right put runners on second and third. Cotts escaped the jam by retiring Jonathan Villar on a groundout to third to strand Marisnick, who was the potential tying run at second.
"We hung around in that game," Houston interim manager Tom Lawless said. "We could have scored a lot of runs. They left 12 guys on base and we're still in the ballgame, 2-0. We just couldn't put anything together offensively until the ninth."
The Rangers left two men on base in each of the first three innings against Astros starter Brett Oberholtzer. They broke through in the fourth when Chirinos led off with a 405-foot homer to center for his 12th blast of the season.
"I don't know if anybody expected him to hit 12," Bogar said, "but he can square something up and drive it real well. ... Chirinos is evolving himself as a hitter, too. He goes up there with a lot more confidence every time."
The Rangers collected 12 hits in all, including three apiece from Adrian Beltre and Jake Smolinski, along with two from Ryan Rua.
Texas has won 10 of its last 11 games, an impressive feat for any team but even more remarkable for a club that was recently on pace to lose more than 100 games. The win also clinched a fourth consecutive series victory.
"We're just having fun," Smolinski said. "We're just kind of expecting to win right now and it seems like we're just doing whatever we need to do to pull the games out."