BALTIMORE - There's no arguing that Wei-Yin Chen has been among the main reasons the Baltimore Orioles' pitching staff has been one of the best baseball.

And on Thursday, the Taiwanese left-hander provided his best yet.

Chen (3-0) earned the victory in Game 1 of the series-ending doubleheader against the Texas Rangers, allowing two runs on six hits and a walk while striking out five in a career-high 7 2-3 innings.

"Definitely, it's my best outing of the year," Chen said through his interpreter. "Everything worked for me."

That lowered Chen's season ERA to 2.68, which is second-best among Baltimore starters.

The fact that he did it against the Rangers was all the more impressive. Texas had torched the Orioles for 24 runs over the first two games of the series after Baltimore had permitted just 23 over the previous nine games combined.

"This is a really tough lineup for me," Chen said. "Because I'm a new guy, they don't know me know much."

One game after Josh Hamilton became the 16th player to hit four homers in a game, Chen quieted the Texas outfielder's bat, holding him to a 1-for-4 showing at the plate.

"I'm not afraid to walk him," Chen said. "I don't think about it too much because I have a really good catcher to guide me. That's why I pitched well today."

Orioles manager Buck Showalter was quite pleased with Chen's performance, especially one start after the 26-year-old allowed a season-high four runs (three earned) in five innings Friday at Boston.

"Wei-Yin was a difference-maker today to get that deep in the game, and against obviously a good lineup. He was outstanding," Showalter said. "He was sharp with his breaking ball, the extra days' rest. It seems like he had a little bit more finish on his fastball.

"He was a difference-maker for us today and it won't be forgotten."

STRANGE START: Texas starter Colby Lewis made all kinds of history on the way to taking the loss for Texas in Thursday's first game.

In seven innings of work, Lewis surrendered six runs on five hits, all of which were homers. The five homers allowed were a career high, and so were his 12 strikeouts. Lewis became the first pitcher since 1918 to give up five homers and strike out at least 10 in the same start. It was just the fifth time of the modern era that a pitcher gave up at least five hits and they were all homers.

In the middle of all that, the right-hander retired 18 in a row.

HAMMEL UPDATE: Before the games, Showalter told reporters that right-hander Jason Hammel's next start could get pushed back to Monday or Tuesday.

Hammel was originally scheduled to pitch Thursday, but did not because of right knee soreness.

Hammel has been Baltimore's best starter, going 4-1 with a 2.09 ERA in his first six starts since being acquired from Colorado in the Jeremy Guthrie trade.

CHAVEZ SHELVED: Between the two games of the doubleheader, the Orioles placed outfielder Endy Chavez on the 15-day disabled list with a left oblique strain.

The move was done to make room for right-hander Tommy Hunter, who was called up from Class AAA Norfolk to start Thursday's second contest. Hunter had been demoted to the Tides Monday to create space for the additions of two relievers. He did not pitch in the minors and was able to return less than 10 days after being sent down because of Chavez's injury.

Chavez has struggled in his first year with the team, batting .133 with one RBI in 20 games.

EVELAND TO START: Showalter announced that left-hander Dana Eveland will be called up from Norfolk to start tonight's series opener against the Tampa Bay Rays.

Eveland, 28, was acquired from the Los Angeles Dodgers in December. He is 3-2 with a 2.21 ERA in six starts with the Tides this season.

A corresponding move will be made before the game. Hunter or reliever Stu Pomeranz could be demoted to make room. Placing Hammel on the DL is another option.