The Coyotes were at their counterattacking best early in the second quarter, with Smith getting the puck out quickly to pick up an assist on Brule's breakaway goal.
The Blackhawks have been resilient all series, though, and kept clawing until Leddy scored from the right point midway through the third period on a shot Smith had trouble seeing after being clipped on the mask by Chicago center Dave Bolland.
"They were coming hard," Coyotes coach Dave Tippett said. "That was their season on the line for them, so you knew they were going to come hard."
And they kept coming in overtime, getting the big play at the right time instead of the Coyotes.
Scrambling off a faceoff, Toews gathered a loose puck near the right circle and let it fly. Unlike the previous two games, when Chicago couldn't beat Smith in overtime, Chicago's captain managed to slip one past, sending the Blackhawks back to the Windy City with momentum blowing on their side.
NOTES: LW Viktor Stalberg was called for all four of Chicago's penalties. ... The Blackhawks are 0-10 when trailing a series 3-1. ... Brule's goal came in his fourth playoff game. ... Chicago is 1-for-17 on the power play in the series after failing on four chances in Game 5.