Cruz's blast in the fifth inning off Carlos Villanueva (6-3) erased a 1-0 deficit and provided all the offense the Rangers would need.
Texas starter Roy Oswalt went 4 2/3 innings, yielding one run on two hits, while Robbie Ross and Tanner Scheppers followed with a combined 1 2/3 scoreless frames.
The American League West-leading Rangers evened their three-game series with the win.
Villanueva surrendered a pair of runs on four hits in a 6 1/3-inning effort.
Adeiny Hechavarria knocked in the only run for the Blue Jays.
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