TORONTO — A goalkeeper’s career can be defined by a single moment.

There’s cruelty in that reality: hours upon years upon decades of hard work coming down to a millisecond of raw instinct. Lives have been ruined, reputations tarnished, by a fleeting misstep.

There can be beauty in it, too, as Seattle’s Stefan Frei found out late Saturday night at BMO Field.

For as long as Frei plays, he is likely to be remembered first and foremost as the man who saved the Sounders’ first MLS Cup title with a desperate flick of his wrist.

Frei’s save of Jozy Altidore’s goal-bound shot in the 108th minute preserved a 0-0 draw, and Seattle triumphed on penalty kicks. Roman Torres converted the decisive kick in the sixth round of the shootout, the Sounders edging Toronto by a tally of 5-4 for the club’s first league championship.

Three years to the day that Frei was traded from Toronto to Seattle for a conditional draft pick, he and his Sounders teammates lifted a long-sought silver trophy in his old stadium.

The Sounders made history as the first MLS champion not to record a single shot on goal in regulation. Seattle’s three total shots were also the fewest managed in any of the league’s 21 championship games. They won’t be dwelling too much on that statistic on the celebratory flight home.

Marveling over Frei’s save might last them all the way through Manitoba and Saskatchewan.

“That’s the best save I’ve ever seen in person,” Seattle defender Chad Marshall said. “It was unbelievable. No way should he have gotten there.”

For most of the opening 90 minutes, Frei’s biggest concern was just staying limber.

With the wind chill factored in, temperature at kickoff was somewhere in the low teens. A brisk wind blowing in off Lake Ontario didn’t help.

For field players, cold weather doesn’t change much, other than adding an extra level of pain into especially crunching tackles. Goalkeepers are the ones you have to worry about. Frei tried to keep moving, to keep the blood flowing, but there’s only so much one can within the constrains of his own penalty box.

“To be honest, after the game was done, I was so cold,” Frei said. “It was nice, because it kept reminding me that it wasn’t a dream.”

Frei had already thwarted Altidore once before his defining moment, when he sprung off his line in the closing moments of regulation to punch the ball away with the TFC forward lurking on the doorstep.

The save a few minutes into the second period of extra time required a whole different level of dexterity.

Altidore leaned back to get just the right amount of loft on his header, and it certainly looked destined for the top corner of the net. Frei backpedaled quickly, following the path of the ball. He sprung, arching his back, to his left. Stretching just about every muscle in his body, Frei was able to push the shot wide with the fingertips of his left glove.

Watching from the sideline, the margins were so thin that Sounders veteran Zach Scott was worried Toronto would call for a video review. Altidore certainly thought it was in.

“It was a hell of a save,” Altidore said. “At the end of the day, you’ve got to pull off something special.”

Added Sounders goalkeepers coach Tom Dutra: “That’s one of the best saves I’ve ever seen in a final. I thought we were done. I was already thinking, ‘You’ve got to give Jozy credit, because he knew exactly what he was doing.’ “

Dutra saw something special in Frei from the moment he arrived in Toronto, on the back end of two seasons marred by injury. Dutra is the one who urged former coach Sigi Schmid to stick with the ‘keeper even when he struggled early on with the Sounders.

Dutra was one of the first ones Frei wrapped in a bear hug after Torres dispatched the crucial PK.

Altidore had netted the first spot kick for Toronto before Brad Evans answered for Seattle, the drama excruciating. TFC’s Michael Bradley blinked first, his weak shot saved by a diving Frei, but Clint Irwin evened the score with a block of Alvaro Fernandez’s effort.

Toronto’s Justin Morrow opened Round 6 with a shot off the bottom of the crossbar and out. Torres followed with the championship-winner. None of it would have been possible without the save that defined Seattle’s defining night.

“Sometimes you surprise yourself with the shots you can actually get,” Frei said. “In that moment, anything can happen.”

For the few fortunate ones that actually get there, that single moment can last a lifetime.

Jane Gershovich | Sounders FC Seattle Sounders FC takes the stage and the championship at the MLS Cup. The Sounders defeated Toronto FC 0-0 (5-4) on Saturday.

Charis Wilson | Sounders FC Seattle Sounders FC Goalkeeper Stefan Frei motions to the crowd cheering his name following his stellar MLS Cup game and MVP award. Seattle celebrates its first MLS Cup with a 0-0 (5-4) win over Toronto FC on Saturday.