Oberholtzer has seen nothing but victories since he rejoined the rotation Saturday in Seattle, and he pitched the Astros to their seventh win in a row in Friday night's Civil Rights Game by holding the Orioles to four hits and one run in seven innings in a 2-1 decision before 38,482 fans at Minute Maid Park.
"We have more confidence," Oberholtzer said. "We got off to a rocky start, especially myself. From being back, confidence I would say is the key."
The Astros rallied to take the lead in the seventh on back-to-back RBI doubles by Robbie Grossman and shortstop Jonathan Villar, who snapped an 0-for-26 drought with a ground-rule double into the right-field gap to score Grossman with the winning run.
On a night Jose Altuve and George Springer, who had been carrying the team offensively, went a combined 1-for-8, it was Grossman and Villar saving the day. Springer went 0-for-4 to snap his 11-game hitting streak.
"For them to be the two offensive heroes tonight, it definitely feels good, and I'm pretty sure they feel good about it as well," Astros manager Bo Porter said. "They've been working extremely hard, and to be able to come through for the team tonight -- especially with two outs, after a poor baserunning decision -- to pick the team up, that's what teamwork is all about."
It's the Astros' longest winning streak since reeling off seven in a row July 27-Aug. 3, 2010. They're 15-13 in May and will finish a full month of the season with a winning record for the first time since September 2010.
"I feel like we're never out of a game," Grossman said. "We're just out there having fun and letting the results speak for itself."
The victory capped a day of celebration in Houston that included the Beacon Awards Luncheon, which honored Motown founder Berry Gordy, Pro Football Hall of Famer Jim Brown and author and poet Maya Angelou, who passed away earlier this week. Brown and Gordy were recognized prior to the game, and two-time heavyweight champion George Foreman threw out the ceremonial first pitch.
Oberholtzer (2-6) then took the ball and fired seven innings for his second consecutive win. He needed only 81 pitches, becoming the first Astros pitcher since Bud Norris on Sept. 14, 2011, to pitch at least seven innings on 81 pitches or fewer.
"Early, I didn't have my stuff," Oberholtzer said. "I just told myself to keep pushing, compete. The final result was good. We got a win."
Oberholtzer is 2-0 with a 2.08 ERA in his last two starts and has put himself in good position to remain in the rotation, which has been at six starters for the past week. Porter said he will go back to five starters beginning Tuesday.
"Well, he threw the ball tremendous," Porter said. "If you can pitch, and you're putting up zeros, we will find some place for you to pitch."
Chad Qualls picked up a four-out save to close out his fifth game of the season. He hasn't allowed a run in his last 14 appearances as the Astros' bullpen improved its team ERA to 1.17 in its past 17 games.
"You come to the field expecting to win," Qualls said. "It helps we've been playing good baseball. Our starters have obviously been throwing deep into the game and keep us in the game, and that's where it all begins. If they keep going deep in the game, our offense will come around. Lately we've won a few games by scoring a lot of runs, and we've also won the close ones."
The Astros, whose offense has been roaring in the last few weeks, didn't get their first hit off Miguel Gonzalez (3-4) until Altuve's one-out infield single in the sixth to extend his hitting streak to nine games with his 77th hit of the season. He stole second base, but was stranded.
Dominguez led off the seventh with a double into the right-field corner and was still at first with one out when Alex Presley shot a single to right. Dominguez, who doesn't run well, was held at third base on the throw to the plate, but Presley tried to take second and was thrown out by catcher Caleb Joseph.
"The only time you're going to continue to run there is if you're saying to yourself, 'I'm going to exchange this out for the run,'" Porter said. "There is no run because there's no play at the plate, because [Dominguez] is slow."
Grossman followed with a double over the head of left fielder Steve Pearce to score Dominguez and tie the game, and Villar came through with his game-winning double to send Baltimore to its fourth consecutive loss.
"It is a rough stretch, I will tell you that," Pearce said. "It's no fun losing, especially when we see the potential that's here. We just can't seem to get the timely hit when we need it."