Jesse Litsch (12-8) worked six innings to get the win, scattering four hits and striking out six. B.J. Ryan put runners on second and third with only one out in the ninth, but worked out of the jam to record his 31st save.
Toronto faced a 2-1 deficit going into the sixth, but Garrett Olson (9-9) walked Vernon Wells to open the inning. Wells was erased on a fielder's choice grounder from Adam Lind and Scott Rolen flew out to give Olson a chance to escape the inning.
Lyle Overbay, however, singled Lind to second and Jim Miller came in to relieve Olson.
Zaun was called on to pinch hit for Curtis Thigpen and, after the runners moved up on a wild pitch, Zaun doubled to right.
Toronto has recorded back-to-back victories and Baltimore has dropped four out of six.
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