Toronto Blue Jays (77-71) at Baltimore Orioles (89-60), 8:05 p.m. (ET)

(SportsNetwork.com) - The Baltimore Orioles try to move one step closer to their first American League East title in 17 years on Monday when they open a three-game series with the Toronto Blue Jays at Camden Yards.

Baltimore comes into the contest with a magic number of three to clinch their first division crown since 1997 and should it take two of three from the Blue Jays it would clinch the crown in front of its fans for the first time since 1969.

The Orioles stand a great chance at trimming the number even further on Monday behind lefty Wei-Yin Chen, who has won eight of his last nine decisions and is 15-4 with a 3.59 ERA. Chen flirted with a perfect game on Wednesday in Boston, but eventually wound up surrendering a run and three hits in seven innings. He had been perfect through five innings.

"It comes across your mind, but still a perfect game is very difficult to do," Chen said through his interpreter. "I just tried to concentrate on each at- bat, and if I had it, I had it. If I don't, it's OK."

Chen has faced the Blue Jays once this season, taking a loss in a four-run, five-inning performance. He's 0-2 with an 8.10 ERA in two career starts versus Toronto.

Baltimore took three of four from the New York Yankees over the weekend, as Kelly Johnson's RBI double in the ninth inning lifted the Orioles to a 3-2 walk-off victory on Sunday.

After Brian McCann's home run provided the Yankees with a 2-1 lead in the top of the ninth, the Orioles rallied in the home half. Nelson Cruz smacked a leadoff double to left off David Robertson (2-5) to start the frame. Quintin Berry replaced Cruz as a pinch runner and soon raced home on Steve Pearce's double to left, which tied the game.

J.J. Hardy flied out to right before Johnson, who played 77 games with the Yankees earlier this season, smacked an elevated first-pitch cutter to right to bring in the game-winning run.

Darren O'Day (5-1) earned the win despite giving up a home run in the ninth. Starter Chris Tillman gave up one run on five hits with six strikeouts over 6 2/3 innings for the Orioles, who took three of four from the Yankees.

Toronto's faint playoff hopes took a hit over the weekend, as they dropped two of three to the Tampa Bay Rays, including Sunday's 5-4 setback in 10 innings.

Adam Lind clubbed a three-run homer and Edwin Encarnacion added a solo blast in the loss for the Blue Jays, while starter Mark Buehrle gave up four runs on nine hits over his six-frame outing.

Brandon Morrow (1-3) was charged with the lead run over his one-plus innings in relief.

"This time of year, there's really no room for error," Toronto manager John Gibbons said. "It's one of those games where not much is happening, and you come back, strike quick, and now the momentum's on your side, and everyone is upbeat and you come back and end up dropping it like that."

Getting the call for Toronto on Monday will be rookie right-hander Marcus Stroman, who has won his last three starts.

Stroman tossed a three-hit shutout on Monday to beat the Chicago Cubs. He also struck out eight and did not walk a batter, as he improved to 10-5 to go along with a 3.61 ERA.

"I used to be a high-pitch guy," Stroman said. "Five innings, six innings, ton of pitches and high punchouts, and now I feel like I'm really learning how to pitch. Using that pitch, I'm able to go deeper, keep the ball on the ground, get double plays when I need them."

Stroman, who recorded 14 of his 27 outs via ground balls, became the first Blue Jays rookie to toss a shutout since right-hander Dave Bush did it on Oct. 1, 2004.

"I've always wanted a sinker, I could just never find a grip that was comfortable for me," Stroman said. "I was lying in bed one day, fooling around with the ball, kind of gripped a two-seam kind of awkwardly. It was super comfortable in my hand, and the next day I came to the ballpark and ever since then I've been throwing it."

Baltimore is 7-6 versus the Blue Jays this season.