Arencibia had three hits and five RBI in the contest, which earned Toronto a split in the twin bill and kept the Orioles 1 1/2 games out of first place in the AL East.
Ricky Romero (9-14) earned his first win since June 22. Romero allowed four runs on eight hits in five-plus innings.
Wei-Yin Chen (12-10) took his third loss in his last six starts. The Baltimore rookie coughed up five runs on nine hits in five-plus innings.
Baltimore had a solo home run from Nate McLouth and two RBI from Robert Andino.
'Happy' fan videos make Pharrell cry [VIDEO]
Pregnant Mila Kunis wins 'Best Villain' at MTV Movie Awards