AP Sports Writer
CLEVELAND (AP) -- Bud Norris has long dreamed of pitching with October baseball on the line.
With one month left, he's got the Orioles in the mix to push their season past September.
Norris stayed unbeaten as a starter with Baltimore and Nate McLouth homered and had three RBIs, leading the Orioles to a 7-2 win over the reeling Cleveland Indians on Monday night in a matchup of two teams scrapping for an AL wild-card berth.
Norris (10-10) allowed one run -- a homer in the seventh to Jason Kipnis -- and four hits in seven innings.
The right-hander improved to 4-0 as a starter with the Orioles, who acquired him at the July 31 trading deadline from Houston. He lost once in relief, but so far has been everything Baltimore hoped.
"It's been a great transition," said Norris, who left baseball's worst team for one climbing to the postseason.
"It's been something I've dreamed of as kid -- to be in a pennant race. To be here in Baltimore, I'm very happy with everything around me, the teammates and organization. I try to do everything I can to help us win games."
Matt Wieters hit a two-run homer in the ninth and Brian Roberts drove in two runs for the Orioles, who came in three games behind Oakland and Tampa By in the wild-card race.
The Indians lost for the sixth time in seven games and could be without All-Star Justin Masterson (14-10) for the most important stretch of their season.
Masterson left his start in the second inning with what the team said is "soreness" in his rib area. He will undergo an MRI and further tests on Tuesday, and those results could swing Cleveland's postseason chances.
"Hopefully it's nothing serious," Kipnis said. "Definitely love to have the big fella out there for us. He's our ace."
After dropping two of three in Boston and New York, the Orioles, who staggered through a 12-14 August, arrived in Cleveland needing to string some wins together.
"I knew that schedule was going to be a challenge," manager Buck Showalter said before the game. "We're .500 in our last 10 games. Is it half full or half empty?"
Norris provided some more optimism, striking out eight and keeping his record unblemished in seven starts since joining Baltimore. He allowed just one hit through five innings, and picked Michael Brantley off second in the second.
"We understand where we are," Norris said. "We're right in the thick of things. We're going to do it one day at a time because you can't get too far ahead of yourself."
Showalter wants his players thinking big, but knows there's a fine line between contending and completing their goals.
"It's a roll of the dice in September," Showalter said. "We want to be more than relevant. It's about doing the things it takes to stay in it. It usually starts with your starting pitching. Bud was the difference maker today."
The Indians are sliding in the wrong direction.
They went 1-5 on a trip to Atlanta and Detroit, and now could be without their best pitcher.
Masterson initially showed discomfort while working to Wieters leading off the second. Masterson grimaced and flared his elbow at his side, a motion that sent Francona to the mound accompanied by a trainer.
The right-hander stayed in the game, but after allowing a single to Wieters, he threw an 87 mph fastball to Nick Markakis and paused.
Shortstop Asdrubal Cabrera went to check on his teammate and immediately waved toward the dugout, bringing Francona again. He took the ball from Masterson, who dejectedly walked off the field and then disgustedly tossed a cup of water in the dugout before heading to the clubhouse.
The loss of Masterson for any amount of time would be a major blow to the Indians and their postseason hopes.
He's their unquestioned ace, leading the team in wins (14) and innings (190 1-3), and the 28-year-old is tied for the league lead with three shutouts.
"You hate to see that," McLouth said. "I feel really bad for him. He can go through stretches of a game where he's so dominant. It does make a difference."
Preston Guilmet replaced Masterson and gave up a single to Markakis. With one out, McLouth hit an apparent RBI double to center.
However, the Indians won an appeal that Markakis missed second base, and under rule 10.05, McLouth was not awarded a hit on the play because it was a forceout.