It didn't happen immediately, but Orioles left-hander Wei-Yin Chen slowly is emerging as the pitcher who excelled for the club in its surprising 2012 playoff run.

That could be a huge development for a team that sits alone, at least for now, atop the American League East standings.

Chen tied a season high with seven strong innings Friday night as the Orioles beat the Houston Astros, 4-3, before an excitable, announced crowd of 28,875 at Camden Yards.

“Yeah, it's always there. It's not like it's something he never shows,” Orioles manager Buck Showalter said of Chen's form during his recent run of solid starts. “Wei-Yin had a good look.”

The first-place Orioles (19-14) have won four straight and seven of their last nine games while the Astros (11-25), baseball's worst team, have dropped eight of 10. This is the Orioles' longest winning streak since July.

“It's been great. Winning some ballgames and winning in great fashion, too,” said first baseman Steve Pearce, who has homered three times in his past four games. “It's been fun for myself and the team.”

After giving up eight total runs in his first two starts, Chen (4-2) has yielded just a combined 10 runs in his past five starts and has won four of five decisions. His ERA is now 3.95.

“I just try to allow as few runs as possible, and [in] the first two outings this year, I allowed more runs” than I wanted, Chen said through interpreter Louis Chao. “So the only goal I want to achieve is to allow the fewest runs possible. That's all.”

On Friday, he surrendered just two runs on five hits and a walk while striking out four. Former Oriole L.J. Hoes hit a sacrifice fly in the third and Chris Carter homered in the seventh against Chen, who again succeeded by getting his breaking pitches over for strikes. It's something he's been working on this season.

“In the previous outings, I was trying really hard, so [pitching coach] Dave Wallace told me I should not try to overthrow my curveball, just go with it,” Chen said. “I tried to do it, and tonight the result was pretty good.”

Chen was locked into a pitchers' duel heading into the bottom of the seventh, but the Orioles scored twice against veteran reliever Jerome Williams.

Rookie Jonathan Schoop broke the tie with a two-out single to score J.J. Hardy. It was Schoop's fourth RBI in the past three games; he had none in his previous eight contests.

“It's going really good. I'm delivering at the big time,” said Schoop, who is batting .235 with 14 RBIs in 102 at-bats. “I'm just trying to keep it simple, not trying to do too much in those situations.”

Schoop scored the eventual game-winner on an RBI double by Nick Markakis, who also had two singles while extending his hitting streak to 16 games. Markakis is batting .354 with two homers and eight RBIs in that span.

“Someone announced he had a 16-game hitting streak. I didn't know that. I bet he doesn't know, either,” Showalter said of Markakis, who is batting .314 this season. “He's healthy, strong. He worked real hard this offseason for the first time that he was able to in a long time.”

Darren O'Day threw a scoreless eighth and closer Tommy Hunter, pitching for the third time in four nights, picked up his 11th save in 12 chances. In classic Hunter fashion, it was a little dicey. He pitched around a leadoff double and allowed a run, but induced a double play and strikeout to preserve the victory.

The Orioles scored twice in the third on solo homers by Pearce and Manny Machado against former teammate Scott Feldman (right biceps tendinitis), who was activated from the disabled list Friday.

It's the first time in Pearce's career he has homered in consecutive games. He is hitting .300 with six RBIs since being released and then re-signed as a fill-in at first for the injured Chris Davis.

“Stevie's made a real contribution, like we thought he would if we could bring him back in the fold,” Showalter said. “Obviously, we've got to make room for Chris in the near future, so that will be another tough call.”

Davis (strained left oblique), who will bat second and play first base Saturday night for Double-A Bowie in a rehabilitation game, could be activated Sunday or Monday, and immediately would start. But Pearce presumably has shown enough to stick around.