The week leading up to the 100th edition of the greatest rivalry in American soccer, Portland Timbers against Seattle Sounders, was a celebration. The 100th edition itself, played Sunday in scorching heat at Providence Park, was not.

Instead, and fittingly, it was a proper rivalry match: tight, physical, frustrating, exhausting, scoreless for 86 minutes, and decided in the end by a single stroke of brilliance in a cauldron of noise and color that was worth its stage.

The Sounders, missing as many six starters, having played on Wednesday night, gave most everything they had to escape Portland with a point. But that moment of brilliance belonged in the 86th minute to Sebastian Blanco, who, along with his Chucky mask, will enter this rivalry's lore.

Seattle's mission coming into the game was clear. With Osvaldo Alonso and Will Bruin both held out with minor injuries, and four more starters on the shelf with longer-term problems, Schmetzer trotted out the same 5-4-1 that carried the Sounders to an upset 2-1 win in Toronto on Wednesday night.

From the opening whistle, Seattle picked up where they left off midweek — sitting nine players behind the ball, allowing easy possession up to the final third, locking down the spaces in and around the penalty area, and letting the Timbers, tasked with trying to break a team down for the first time this year, labor.

And labor they did. Save for one or two quick combinations, the Timbers found the middle of the field impassable and did no better in wide areas. They failed to test Stefan Frei in the first half, and wouldn't put their first shot on target until the 68th minute.

It was a slog. The heat ground down the place of play, which only further diminished Portland's ability to move Seattle's entrenched, competent backline.

In fact, the biggest moments of the opening period were both disciplinary: Jordy Delem was extraordinarily lucky to remain on the field after a horrible challenge on Diego Valeri, for which he was, shortly thereafter, cleaned out by Liam Ridgewell.

All told, the game was playing out just as Schmetzer had hoped it would. The Sounders even enjoyed some easy possession of their own after the restart, with Nouhou hitting a decent look tamely at Jeff Attinella after charging into acres of space down the righthand side.

When the Timbers did finally get themselves going again, they quickly carved out their best chance of the game.

Valeri cut inside from the right and played Fanendo Adi, whose sharp return sent Valeri through on goal — only for Gustav Svensson to come flying in from out of the play and making a sliding block on his shot. It was a spectacular piece of defending, and it easily could have been the game's decisive play.

As the second half wore on, it settled into a familiar pattern: both teams well organized and limiting mistakes, the Timbers searching for daylight without luck, and the Sounders defending well while continuing to be decimated by injuries.

Nouhou, who'd pretty well dominated his respective matchups with Alvas Powell and Polo, went down on the hour mark. Kim Kee-Hee collided with Adi and was replaced ten minutes later. Delem moved to center back, while Jordan McCrary — a USL player at this time last year — took over on the right.

Schmetzer had played just about every card in his deck, and still it looked for all the world like his team was going to have enough to hold on. Then, all of the sudden, four minutes from time, the Timbers finally broke through.

Sam Arementeros, whom Giovani Savarese had introduced alongside Andre Flores with fifteen minutes to go, received an entry pass from Larrys Mabiala, took a heavy touch, ran into Christian Roldan, knocked the ball free, and then cleaned out all three Seattle center backs with an absolute gem of a through ball.

The right man was racing onto the end of it. On an afternoon when the Timbers needed to will a goal onto the scoreboard, no player was more active, direct, and dangerous than Blanco. Here he glanced up at the onrushing Frei, and lifted the ball over the goalkeeper's left shoulder and into the far corner.

Providence Park exploded. In an instant, the Sounders' game resistance had been washed away.

After a full ten minutes of stoppage time, which including two more trips to the broiling playing surface for the Seattle trainer and a video review of a late Blanco tackle on Delem, referee Robert Sibiga, having somehow kept 22 players on the field and whistled just 12 fouls, brought the curtain down.

It was an absolute battle. Not pretty to play, not pretty watch, but hugely, abidingly satisfying to win. For Savarese, who left the field smiling, white shirt drenched in sweat, it was a fabulous introduction to the rivalry.

His smile was well-earned. Once again, his team found a way. The Timbers remain unbeaten at home, now winners of four straight, riding a 280-minute shutout streak, and above the playoff red line for the first time this season.

The defense, again, was superb. Mabiala and Ridgewell led the way, but Cristhian Paredes was bright also, while Diego Chara's fifteen defensive actions were the most in the game and didn't include his sixty yard chase-down of Clint Dempsey that resulted in Dempsey dribbling the ball over the end line.

Isolated up top and unable to create on his own, Dempsey made an unusually quiet account of himself. This defeat is his first suffered in Portland since the 2013 season, and, alongside Alonso's no-show, a nod to the power of time.

The Sounders, as in most every year around this time, are in trouble. They're old, banged up, and bottom of the West. Chances are that they'll be a different team when they next meet the Timbers at the end of June in Seattle, and a radically different team when they return to Portland at the end of August.

This was, after all, for all it took to contest, just the first of three installments of this rivalry in 2018. It was Chara who described the Timbers-Sounders as "an arm wrestle that never ends," and he, having played in this game more than almost anyone else, would know.

So it never ends, between Portland and Seattle. It just stops, for small moments, and on this Mother's Day in Portland, it stopped as Blanco's chip settled in the corner, a milestone passed, and more to come.