Mikkel Boedker scored his second straight overtime game-winner to give visiting Phoenix a commanding 3-1 edge in their Western Conference quarterfinal series against Chicago.
Boedker, who won Game 3 in overtime, outraced Chicago's defense and appeared to loose control of the puck but it slid underneath Blackhawks goaltender Corey Crawford for the victory at 2:15 of the extra session.
Shane Doan and Taylor Pyatt also scored for the Coyotes, who blew a two-goal lead in the final 10 minutes before Boedker's heroics.
Mike Smith turned aside 30 shots for Phoenix, which can wrap up the series at home in Saturday's Game 5.
It marked only the second time in league history that a series has opened with four straight overtime games. The other was the 1951 Stanley Cup Finals between Montreal and Toronto.
The Coyotes seemingly took command of the game - and the series - when Doan and Pyatt scored 44 seconds apart in the third period for a 2-0 lead with just over 12 minutes to play.