McDonagh put the puck past backup goalie Thomas Greiss, who relieved injured starter Mike Smith in the third period and then gave up the tying and winning goals. Girardi got the Rangers even with 3:26 left in regulation when he tipped in a drive by his defence partner McDonagh.
Brad Richards and Derick Brassard scored in the second period when New York erased a 2-0 deficit Phoenix built in the first. Henrik Lundqvist made 18 saves on a night he was honoured for recently breaking Rangers career marks for wins and shutouts.
The Rangers' fourth straight win pushed them one point ahead of Philadelphia and into second place in the Metropolitan Division.
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