BALTIMORE - The Baltimore Orioles moved to the brink of claiming their first AL East title in 17 years, using a resilient pitching performance by Wei-Yin Chen to beat the Toronto Blue Jays 5-2 Monday night.

Baltimore can clinch the division crown with a win over Toronto on Tuesday. That would assure the Orioles their second playoff berth in three years following a run of 14 consecutive losing seasons.

Baltimore (90-60) leads the AL East by 12 1/2 games, its biggest advantage since 1979.

Chen (16-4) allowed two runs on nine hits over 5 2-3 innings to become the first Orioles lefty to win 16 games since Jimmy Key in 1997 -- the year Baltimore last won the AL East. Although he yielded at least one hit in every inning but the second, Chen improved to 13-2 in 23 starts since May 9.

Zach Britton worked the ninth for his 35th save in 39th opportunities.