Together, they’ve won two MLS Cups, two Supporters’ Shields and a combined 11 domestic cups, with Toronto winning the Canadian Championship seven times and Seattle topping the U.S. Open Cup on four occasions.
Along the way, they’ve shared plenty of history and provided many memorable moments. Here’s a look at some of those top imprints in time as the Audi 2019 MLS Cup Playoffs near their end.
Seattle hit the ground running in 2009 as an expansion club, rattling off three straight wins to begin the season. A 2-0 victory at Toronto on April 4 of that year marked the club’s first road win in MLS, and some blasts from the past supplied the goals.
Swedish midfielder Freddie Ljungberg and former MLS SuperDraft No. 1 pick Steve Zakuani found each found net, while Kasey Keller posted a shutout.
Fredy on the spot
Before landing back with Vancouver Whitecaps FC, Fredy Montero got his MLS start with the Sounders in 2009. He even finished with 47 goals and 34 assists for the club in league play before heading overseas to Sporting CP.
One of his best finishes for the Sounders came in a 1-0 win at BMO Field, where he curled home a sumptuous free kick in the 90th minute of a June 19, 2011 match. Standing alongside Ozzie Alonso, the Colombian striker sent it up over the wall and past Stefan Frei – before he was acquired from Toronto via trade in December of 2013.
St. Patrick’s Day prize
Just after St. Patrick’s Day in 2012, Toronto and Seattle met at CenturyLink Field in a 3-1 result for the home side. The scoreline was notable as a standalone metric, but how the Rave Green got there was even more impressive.
David Estrada bagged a hat trick within 46 minutes, marking the third time one Seattle player scored three goals in a match. Up until then, the others were Blaise Nkufo and Lamar Neagle.
Estrada can now be found playing for New Mexico United in the USL Championship, but will always have a moment in this fixture’s lore.
Bloody Big Deal
When Jermain Defoe arrived in Toronto for 2014, his first match was a March 15 visit to Seattle. The English striker didn’t disappoint, as he scored twice in a 2-1 win, marking a pair of the Designated Player’s 11 tallies in MLS.
Not a bad way to mark your debut, huh?
Most MLS fans know this one, and they know it simply by name. It’s Stefan Frei’s other-worldly save in the 2016 MLS Cup clash between Toronto and Seattle, the one where he pawed a Jozy Altidore header out of the top corner.
Heck, there was even a mini documentary made about it:
Stefan Frei stops Jozy Altidore: The greatest MLS save of all time
The first MLS Cup meeting between these two sides was decided on penalty kicks, and an unlikely source sent the Sounders into celebrations on a frigid night in The Six.
Center back Roman Torres scored in the sixth round of the 5-4 shootout victory, after Justin Morrow and Michael Bradley both missed their spot-kick attempts. The Panama international called game after a 0-0 draw followed regulation and extra time.
PK GOAL: Roman Torres wins 2016 MLS Cup for SEA!
Vazquez seals it
When Toronto beat Seattle in the 2017 MLS Cup, Jozy Altidore sent the 2-0 victory along its way with an opening strike in the 67 minute.
But the most memorable moment from the match is arguably Victor Vazquez’s insurance tally in the 94th minute. The Spanish midfielder bundled home an Armando Cooper shot that hit the post, sending BMO Field into pure bedlam.
As celebrations ensued in front of the home crowd, Toronto knew their first MLS Cup was signed, sealed and delivered. It was also a fulfilling moment for Vazquez, who had recovered from a grueling knee injury earlier that year.
GOAL: Victor Vazquez seals MLS Cup for Toronto FC
Not today, Alejandro
As a precursor to Seattle and Toronto meeting for the third time in MLS Cup in three years, their only encounter of 2019 came back on April 19 at CenturyLink Field. The Sounders emerged with a 3-2 win, but the noteworthy highlight from the five-goal thriller wasn't even a goal.
Rather, it was a trademark save from Stefan Frei on Alejandro Pozuelo, as the Spaniard was denied an equalizer in the 92nd minute. It was the Spaniard's third game in MLS, and he had already served up two assists to Jozy Altidore earlier in the match.
We can't see into the future, though odds are Frei will need another big-time moment against Pozuelo on Sunday.
SAVE: Stefan Frei makes huge diving save late in the game
What could the 2019 MLS Cup rematch have in store? If you have thoughts on that or any other moments in Toronto-Seattle history, feel free to share below.