The Maple Leafs were 22 seconds away from an opening-round postseason exit for the fourth straight year when Zach Hyman's equalizer sent the game to overtime.
Hyman's tally was Toronto's third goal in 3:34 after the Leafs trailed 3-0 with under four minutes remaining. Auston Matthews then delivered the overtime dagger, and a winner-take-all Game 5 will now take place on Sunday night.
"Jason Spezza did not want our season to end today," Keefe said, according to TSN's Kristen Shilton. "That's a guy not going down literally without a fight."
While the Maple Leafs' big four of Matthews, John Tavares, Mitch Marner, and William Nylander will deservedly make most of the headlines after combining for 10 points, Spezza and the fourth line deserve credit as well.
"He wants it more than anyone," Hyman said of Spezza, per TSN's Mark Masters. "He’s been in the league so long. He was a first-line player throughout his career, an All-Star, Hall of Famer, and now he’s on the fourth line and willing to drop the gloves ... he’s a real leader on our team ... we all love him."
Spezza's line with Kyle Clifford and Pierre Engvall was integral in the victory, playing the second-most minutes together of any three forwards at five-on-five. They dominated play, too, finishing the contest with a 16-5 shot-attempt differential and an expected goals for percentage of 74.6, according to Natural Stat Trick.
Keefe juggled the forward lines to try and find a spark - which included loading up one line with Matthews, Tavares, and Marner - but Spezza, Engvall, and Clifford were the lone trio to stay together from start to finish.
The Leafs' comeback over the Blue Jackets came just one night after they blew a 3-0 lead themselves. Toronto is now the first club in NHL history to overcome a deficit of three-plus goals after surrendering a lead of three-plus goals to lose the previous contest, according to NHL Public Relations.
Additionally, the Leafs are just the second team in league history to score three goals with the extra attacker in a playoff game, joining the 2017 Anaheim Ducks.