Second baseman Ryan Flaherty, left, and catcher Matt Wieters look on as Baltimore Manager Buck Showalter pulls starter Wei-Yin Chen during the seventh inning of a 5-3 loss at Tampa Bay. Chen has dropped his last four decisions. (Steve Nesius/Reuters)

The Baltimore Orioles had a new title Monday here at Tampa Bay. For the first time in 15 years, the Orioles could call themselves playoff bound.

Their 2012 playoff caps hung from their lockers in the visiting clubhouse of Tropicana Field. Several players donned fresh black “O’s for October” postseason T-shirts.

But the Orioles came to Tampa Bay to finish the unlikeliest of missions — winning an American League East title.

But their hopes of winning a division title took a hit Monday night with a 5-3 loss to the Tampa Bay Rays, snapping Baltimore’s four-game winning streak.

The Orioles’ loss — just their fourth in their last 15 games — combined with the New York Yankees’ 10-2 win over the Boston Red Sox, dropped the Orioles one game back with two games remaining.

The Rays scored three unearned runs — keyed by an inning-opening fielding error by third baseman Manny Machado — off Orioles starter Wei-Yin Chen to open up a tie game in the bottom of the seventh inning.

Chen appears to have hit the wall in his first major league season. The 27-year-old left-hander, a Taiwan native who pitched the last four seasons in Japan, has lost four straight decisions and has gone seven or more innings in just one of his last 10 starts.

The Orioles (92-68) brought the go-ahead run to the plate in the ninth three times against Fernando Rodney, but the Rays closer struck out Jim Thome and Mark Reynolds and induced a lazy grounder back to the mound from pinch hitter Endy Chavez to end the game.

Trailing 5-1 heading into the ninth, Chris Davis launched a ball that hit off the C ring catwalk and was ruled a two-run homer for his fifth home run in six games.

Before the ninth, Baltimore scored its only run on Matt Wieters’s 23rd home run, a solo shot in the seventh. But that was all the Orioles managed off of Alex Cobb in his seven innings of one-run ball. Cobb struck out seven and walked two.

Chen found his comfort zone through the middle innings, retiring nine straight after yielding a solo homer to Ben Zobrist to lead off the fourth. But he ran into trouble in the seventh after Machado bobbled Longoria’s grounder for an error.

Jeff Keppinger followed with a single that put runners at the corners with no outs, and the Rays took a 2-1 lead after Ben Francisco’s sacrifice fly to left.

Sam Fuld’s chopper that took a high hop over Reynolds at first and into right field put runners at first and third again.

Chris Gimenez then doubled home two runs with a hit into the right-field corner, putting the Rays up 4-1 and chasing Chen from the game.

— Baltimore Sun