The Baltimore Orioles stunned the Boston Red Sox last September to finish off Boston's epic collapse.
Baltimore has continued surprising opponents to start 2012.
Off to their best start in seven years, the Orioles open a three-game series at Fenway Park on Friday night trying again to beat Red Sox ace Jon Lester for the first time.
This is these teams' first meeting since Baltimore went 5-2 against Boston in the final two weeks of the 2011 season, rallying for a 4-3 victory in the finale to keep the Red Sox - who held a nine-game lead in the wild-card race in early September - out of the playoffs.
Lester (1-2, 4.65 ERA) was in line for the victory in that Sept. 28 game before Baltimore scored twice off Jonathan Papelbon in the ninth.
"End of season like this, to make Boston go home sad, crying, I'll take it all day," second baseman Robert Andino said after getting the game-winning hit.
That was only the second time Boston lost in Lester's 18 career starts against the Orioles. The left-hander is 14-0 with a 2.36 ERA in the series, including 7-0 with a 2.16 ERA in eight starts - all Red Sox wins - at Fenway Park.
The Orioles (16-9), though, arrive in Boston playing extremely well. They took two of three from the Yankees in New York this week, closing the series with a 5-0 victory Wednesday.
Baltimore, which has won eight of 10, held the Yankees to two runs or fewer in three straight games in the Bronx for the first time since 1978.
"It's not near as meaningful as everybody makes it out, they're just one of the teams in our division," manager Buck Showalter said.
While Showalter isn't going to celebrate a series victory in early May, Baltimore's 25-game start is its best since it was 17-8 in 2005 - the last year the team won more than 70 games.
The Orioles hope that momentum helps them break through against Lester, who gave up five hits in seven innings of a 1-0 win at Chicago on Saturday. Lester is looking to become the first pitcher to start 15-0 against an opponent since Roy Oswalt did it versus Cincinnati between 2001-05.
Baltimore's rotation may be able to keep pace, having gone 3-1 with a 1.57 ERA over the last five games. The bullpen hasn't allowed a run in that stretch, giving up three hits over 9 2-3 innings.
Wei-Yin Chen (2-0, 2.22) will try to keep things going as he faces the Red Sox for the first time. The rookie left-hander tossed a season-high seven innings Saturday in a 10-1 win over Oakland.
"I feel like I am getting improved every time I go out on the mound," Chen said through an interpreter. "I feel like I'm getting better and better."
After averaging 7.5 runs while winning six straight, Boston (11-13) has lost three of four, totaling six runs in the defeats. The Red Sox began this homestand by dropping two of three to Oakland, losing 4-2 on Wednesday for their seventh defeat in their last eight at Fenway.
Adrian Gonzalez went 0 for 4, striking out with the bases loaded to end the seventh, then grounding out with a runner on to end the game.
Boston went 0 for 13 with runners in scoring position.
"This game is all on me. I had two great opportunities and I didn't come through," Gonzalez said. "I should have come through one of those times and I just wasn't able to. ... It won't happen again."
Gonzalez is hitless in his last 17 at-bats, striking out five times. However, he batted .486 last year against the Orioles with eight doubles, two homers and 14 RBIs.