TORONTO -- Seattle goalkeeper Stefan Frei came back to haunt his former team as the Sounders defeated Toronto 5-4 in a penalty shootout to win the MLS Cup and end a long, chilly Saturday night.

It was 0-0 after regulation, with Frei keeping Seattle in the game with a marvellous save in extra time.

Jozy Altidore, Benoit Cheyrou, Will Johnson and Drew Moor scored in the shootout for Toronto. Frei stopped captain Michael Bradley and Justin Morrow hit the underside of the crossbar with Toronto's sixth attempt.

Defender Roman Torres then stepped up and beat Clint Irwin to end the drama.

Brad Evans, Andreas Ivanshitz, Joevin Jones and Nicolas Lodeiro also scored in the shootout for Seattle. Clint Irwin stopped Alvaro Fernandez.

It was a bitter pill for Toronto to swallow after a game where the tension was ratcheted up as the night wore on, with Toronto turning the screws. The shots were 19-3 in Toronto's favour (7-0 in shots on target) after 120 minutes but Seattle defended stoutly.

The Sounders' zero shots on target and three total shots were both MLS Cup records. And it was the first 0-0 MLS Cup final in regulation time.

Seattle, which was mired near the bottom of the league in mid-July, becomes the 11th team in league history to win the championship.

Nine of the previous 20 finals had also required overtime with three of those going to penalty kicks.

Toronto had chances in extra time. Substitute Tosaint Ricketts shot just wide early in the second half with Frei rooted to the spot.

The former Toronto FC 'keeper then made a brilliant save in the 108th minute, using his left hand to claw away a looping Altidore header from the top corner. Frei somehow extended himself like Inspector Gadget to preserve the tie.

Torres then had a chance at the back post, but could not sort his feet out.

Toronto had the better chances in the first half but could not break down a well-organized Seattle side. Toronto captain Bradley and Seattle counterpart Osvaldo Alonso both stood out, breaking up plays and sending the ball the other way.

It was a tense second half, with both teams knowing one mistake could cost them the Cup. As the clock wound down on regulation time, Toronto had outshot Seattle 12-3 (3-0 in shots on target). Two of the Sounders shots were off-target and the third was blocked.

It was almost decided in second-half stoppage time but Frei got to a bouncing ball off a Bradley corner just before Altidore did. Frei paid the price, running into the burly forward.

Both teams' star men had quiet nights. Striker Sebastian Giovinco was treated like a pinata by Seattle defenders. Uruguayan playmaker Lodeiro was kept in check by Toronto.

Giovinco came out in the 103rd minute, replaced by Ricketts. He exited late in the last playoff game too, slowed by cramps.

It was -4 Celsius at kickoff but felt like -9. It didn't bother Bradley who wore short sleeves and no gloves.

None of the Toronto starters wore tuques in the warmup. Some of the Sounders, in contrast, looked like they had dressed for the ski lodge.

The championship game, just 15 days before Christmas, was the latest ever on the MLS calendar. The previous latest was Dec. 7, in 2015 and 2013. The temperature at the 2103 final in Kansas City hovered around -6 Celsius (22 F) at kickoff, making it the coldest match since 2003 when the league first started recording game-time temperatures.

At the other end of the spectrum, the 2004 Cup final was a warm 27 degrees (81 F) on Nov. 14 in Carson, Calif.

Not this night. You could see the players' breath and feel for the kilt-wearing flag-bearers during the anthems. Most of the record capacity crowd of 36,045 at BMO Field stood during the match, probably to keep their feet moving.

The travelling Seattle fans likely needed an air traffic controller to find their seats high in the corner of the East Stand.

It was physical from the get-go. Giovinco was floored in the third minute and Moor went down after taking an accidental boot in the groin from Nelson Valdez in the sixth. Toronto's Armando Cooper then ran over Jordan Morris.

The early chances went to Toronto with an Altidore shot deflected wide in the second minute and then Frei getting down to stop a weak shot from Jonathan Osorio in the 15th. Seattle had its moments but could not convert them into scoring chances.

In the 26th minute, Torres took a Giovinco shot to the face. But the big Panamanian was soon back up.

Altidore came close with a header in the 30th off a Morrow cross. Giovinco had two bites at the apple from free kicks in the first half but could not work his magic.

Seattle, looking to strike on the counter-attack, failed to put a shot on target in the first half. Toronto managed three.

Giovinco shot wide in the 49th minute, missing a fine opportunity. Minutes later he was bulldozed into the turf by Alonso with no foul called.

Toronto built the shot count to 10-0 (3-0 in shots on target) after 60 minutes.

Valdez limped off in the 73rd minute, replaced by Ivanschitz. Morris moved to the tip of the Seattle offence.

Giovinco was taken down in the 76th minute, caught in a Sounders sandwich, but again got no call from referee Alan Kelly -- much to the Italian's disgust.

Torres, who was immense on the night, and veteran centre-back partner Chad Marshall did not yield an inch.

Saturday's game pitted two championship-hungry franchise with heavyweight fan followings. Seattle, which joined the MLS fold in 2009, led the league in attendance averaging 42,636 per game at CenturyLink Field. Toronto, which came on board in 2007, was third -- behind Orlando -- at 26,583.

Saturday's big crowd was made possible by temporary seats left over from the Grey Cup.

Pre-game social media messages of support for the home side came from all quarters, from Drake to the prime minister.

"At #BMOField in my long underwear," tweeted TV personality Drew Carey, a minority owner in the Sounders.

The teams each made one change in their midfield from Game 2 of their respective conference finals. Osorio returned at the expense of Johnson for Toronto and Erik Friberg came in for Ivanschitz for Seattle.

There were five points separating the sides during the regular season with Toronto (14-9-11) third in the East and Seattle (14-14-6) fourth in the West.

The Sounders' season turned on July 26 when assistant coach Brian Schmetzer replaced Sigi Schmid, the team's only head coach. Seattle, ninth in the West with a 6-12-2 record at the time off the coaching change, went 12-3-4 since en route to the final.

Toronto also arrived on a roll, having lost just three times since mid-July (12-3-5). The year had a hard start, with Toronto playing the first eight games of the season away due to stadium renovations.

A crowd of 21,700 took in the only other MLS Cup in Toronto in 2010, when the league used to hold the championship at a neutral venue. Colorado, with current Toronto defender Moor in the lineup, beat Dallas 2-1 in overtime. Temperature at kickoff that night was 6 C (43 F).