With the win, the Panthers, who improved their record to an impressive 12-5-5, became just the second team in NHL history to win two games when trailing by four goals in the same season.
"Always great to win," Quenneville said. "This wasn't textbook how we play. I think you get excited when you play the right way and you deserve wins. Tonight, we'll take it. But we've got to be better. The Boston [victory] was highly improbable, and this one was the same way."
Max Jones broke the ice for the Ducks in the first period, whacking a loose puck past Sergei Bobrovsky to put the Panthers in a 1-0 hole at 17:15. Then, in the second period, Nick Ritchie doubled that lead when he converted on a quick one-timer to put Anaheim ahead 2-0 at 7:17.
Later in the middle frame, Rickard Rakell made it 3-0 with a power-play goal at 15:50. Less than three minutes after that, Ondrej Kase capitalized on a turnover to push the lead to 4-0 at 18:39.
At 18:53, Brett Connolly got one back for the Panthers, beating John Gibson with a wrist shot from the high slot to cut the deficit to 4-1. Twenty-seven seconds later, the veteran winger found the back of the net again from a similar spot to make it 4-2 with 40 seconds left in the second.
"Huge," Quenneville said of Connolly's two timely goals. "The first one, all of the sudden it's 4-1 and you think you've got a sniff. Then all of the sudden you get the next one. We've had some amazing comebacks, which I think got everyone excited after two [periods]."
In the third period, Ekblad scored his first of two goals, beating Gibson with a rocket from just below the blue line to cut the deficit to 4-3 at 11:55. With time ticking down in regulation, newly-recalled Dominic Toninato scored from the doorstep to make it 4-4 at 15:37 and force overtime.
Of Bobrovsky's 28 saves, 10 came in the third period.
"We need him to make some key saves because we're opening it up and taking some chances," Quenneville said of Bobrovsky, who has won each of his last games to improve to 9-4-4. "You hope not, but there's going to be some odd-man situations against you… They did have some quality, all-alone looks, and he made some great, great saves."
After Aleksander Barkov won the opening faceoff in the extra frame, Ekblad skated down the right side of the ice before sending a shot over Gibson's glove for the game-winner at 0:22.