Washington could have used one for his bullpen, as well.
The Rangers got 5 1-3 serviceable innings out of the rookie right-hander, only to see the Houston Astros rally for two runs in the eighth against his relief for a 3-2 win.
"I told him he did his job when he came off the field," Washington said of Martinez. "It was up to the bullpen to finish it off. We had the two best we've got in there and we just didn't do it."
Matt Dominguez hit a tying homer and Jose Altuve's fourth hit drove in the go-ahead run for Houston.
Dominguez connected off reliever Neal Cotts (2-8) with one out in the eighth to make it 2-all.
Marisnick, who had been hit by Cotts to get on base, stole second, setting up Altuve.
"You don't want to give free passes away that late in the game, and it came back to haunt me," Cotts said. "Came back to haunt us."
Martinez allowed one run and six hits. He struck out four and walked three. He loaded the bases in the third on back-to-back walks, but escaped unscathed.
"I felt good," he said. "I just ran into one long inning that kind of took me off-track. I tried to get back on track and had another one quick inning after that and then just fell behind some hitters that last inning in the sixth."
Dallas Keuchel went seven innings for the Astros, allowing two runs and five hits. He struck out three and walked two.
Rios doubled and scored on Ryan Rua's grounder in the first inning.
Washington lamented his team's inability to add to the score. Texas left six on base and were 2-for-7 with runners in scoring position.
"We put ourselves in position to maybe add on and didn't do it," he said. "We still had the lead going into the part of the game where we had our two best pitchers in there."
The Rangers are keeping a close eye on RHP Miles Mikolas as they decide on the fifth spot of the rotation.
"Let's see how Mikolas is," Washington said. "If we feel we need to miss him another start we can always fill it with (Scott) Baker. Robbie (Ross Jr.) is in the mix, but we'll see where it goes."
Rangers: Whether RHP Yu Darvish (right elbow) can return to the mound this season remains unclear. "I don't know," Washington said. "Waiting until Dr. (Keith) Meister tells him he can pick up a baseball to make a decision." Darvish was placed on the 15-day DL Aug. 13, retroactive to Aug. 10.
Rangers: Lewis (9-11) looks to build on his previous outing — his second complete game of the season, snapping a three-game losing streak — when he starts Monday night at Kansas City.