The game had been tied 6-6 since the second inning until Detroit finally pushed across a run in the eighth.
That brought up Hunter, who scorched a grounder off Wagner's legs. The ball bounded to shortstop Jose Reyes, whose throw to first was barely late, allowing Infante to score the decisive run.
Hunter finished 4-for-5, Miguel Cabrera smacked a three-run homer -- his 26th round-tripper of the year -- and Avila drove in a pair of runs as Detroit rebounded from an 8-3 loss in Monday's series opener.
Al Alburquerque (1-1) was credited with the win thanks to a scoreless seventh inning and Joaquin Benoit earned his sixth save for the Tigers.
Colby Rasmus belted a two-run homer and finished with four RBI for the Blue Jays.