By Daniel Trotta

NEW YORK (Reuters) - Baltimore's ability to defy the probabilities of baseball has carried the Orioles into a deciding Game Five of their American League Division Series against the New York Yankees.

With their 13-inning 2-1 victory over the Yankees on Thursday, the Orioles improved to 8-0 in games that have gone 13 innings or more in 2012.

Some call it luck, others may say it is magic. The Orioles have a simpler answer: the bullpen.

The seven Baltimore relief pitchers used in Game Four shut out the Yankees, a team that finished second in baseball in runs and first in home runs this year.

Such performances have helped put the Orioles, a team widely predicted to finish last in the American League East, one game away from reaching the league championship series.

"You look at our bullpen. They've put us in situations late in games to score or manufacture those runs," said Jim Thome, a 22-year veteran slugger picked up by the Orioles this season.

While lacking the marquee names that the Yankees have, the Orioles improved their record to 31-10 in one-run games with Thursday's victory and an even more remarkable 17-3 in extra inning games.

"Obviously it's fitting with the type of games we've had all year," said Jim Johnson, the closer who notched a league-leading 51 saves during the season and earned the save on Thursday.

"We play better when our backs are against the wall, when we're not supposed to win."

Looking for the best match-ups against the powerful Yankees lineup, Baltimore manager Buck Showalter used his first four relievers for less than two innings combined.

Then with the game extending into extra innings, he needed to rely on right-handed side-arm thrower Darren O'Day for two and two-thirds innings and Pedro Strop for two more before calling on Johnson to finish up.

In seven and one-third innings, the Baltimore relievers allowed just four hits and one walk while striking out six.

"I've never been on a team that's this much fun," O'Day said. "Just look where we came from at the time we reported to spring training. Everybody thought we were going to be basement dwellers. They thought we'd be making tee times by now. It's been an awesome journey."

The relievers will have at least one more chance to shine when they battle the Yankees on Friday. The winners will advance to the league championship series against the Detroit Tigers with a berth in the World Series at stake.

"I'm guessing it's going to be a one-run game tomorrow," Johnson said. "I wouldn't expect it any other way."

(Editing by John O'Brien)