In his debut, Britton struggled with confidence and control, walking six, but Sunday, he went six scoreless.
Luis Ayala and Jim Johnson had their hands full getting out of the ninth inning, though, holding off the Indians in a 4-3 victory Sunday at Progressive Field.
Britton (1-0) scattered four hits over six innings, walking a pair and striking out five. He said he had moved on from his rocky start earlier in the week against the Twins, and he pitched that way.
"I just completely forgot about that start and started moving on to my bullpen," Britton said. "That's one of those thing I learned down in Triple-A. Whether it was a good outing or a bad outing, you have to turn the page."
Manager Buck Showalter said the ability to do just that, after great outings and after lousy outings, will be an important part of Britton's ability to mature as a Major Leaguer.
"That's being a professional," Showalter said. "Zach will hopefully want to be consistent. It's tough to do what he did today, but it's even tougher to be consistent."
Britton stayed aggressive in the strike zone most of the way through, but in the sixth inning, he walked two batters and found himself facing Carlos Santana with bases loaded.
Britton got Santana looking for strike three to end the threat, sealing up the fifth straight quality start for the Orioles, who have won five in a row.
"At this level, sometimes it's mano y mano," Showalter said. "You just say, 'Here's the best I got' and see what happens. Where you doubt yourself is when you go back to the apartment and wish you hadn't been so timid there."
Catcher Taylor Teagarden and Britton had the right approach for Santana, who went 3-for-4 Sunday.
"I think we started him off a little soft," Teagarden said. "He had a couple good at-bats, so we knew we had to be careful. We got to 2-2 and hadn't really come [inside] yet. We had a good chance to come in a couple times when I think he was looking outside."
Britton's aggressiveness in the strike zone compounded the Tribe's struggles, skipper Manny Acta said.
"He's got good sink on his fastball," Acta said. "For the most part, we were not aggressive when he was in the strike zone. You can't take anything away from him. He held up pretty good. We continue to struggle, but he threw the ball very well."
After striking out Santana, Britton turned it over to Baltimore's bullpen. The Orioles are a perfect 38-0 in games they lead after seven innings, but the bullpen nearly unraveled in the ninth.
Luis Ayala retired the first seven hitters he faced in relief of Britton, but after Michael Brantley singled and Santana homered, Baltimore's lead had been trimmed to 4-2.
Closer Johnson gave up consecutive hits to the first batters he faced, as Lou Marson's RBI single brought home Shelley Duncan. Johnny Damon flied out to left, bringing up Shin-Soo Choo. Johnson walked Choo, but struck out Asdrubal Cabrera to end the game.
"It wasn't really the way we drew it up, but it seemed to work out," Johnson said. "We got the win, so it doesn't matter."
Johnson recorded his league-leading 30th save.
Johnson had to rely on secondary pitches to get the job done Sunday, part of the reason he walked Choo to face Cabrera.
"I didn't have a matchup I liked, so I forced myself to pitch around Choo," Johnson said. "I didn't like the matchup with the way I felt on the mound today. I felt like I had a better opportunity to get Cabrera for the last out."
J.J. Hardy was an unexpected offensive hero for the Orioles, going 2-for-5 with three RBIs. Hardy's two-run homer in the first off Josh Tomlin (5-7) put Baltimore ahead. Hardy singled in another run in the seventh.
Wilson Betemit's leadoff homer in the eighth inning provided the winning margin.
"At the end of the day, it's about scoring more runs over 27 outs," Showalter said. "We'll take it and move on."