Craig Mitchelldyer/Portland Timbers

The Portland Timbers, be it through missed flights or missed chances or missing players, had their backs firmly against the wall ahead of Sunday afternoon's do-or-die meeting with the Seattle Sounders at Providence Park.

Their response? It was to blow through the wall.

By the time Hilario Grajeda blew his whistle to end the first half, the game was over. The Timbers were 4-0 up, having blitzed their way to one of the most jaw-dropping halves of soccer in the history of the storied rivalry between Portland and Seattle.

The game would eventually finish 4-2 to Portland, but it will be long remembered for its opening stanza β€” one in which the Timbers came on like a bigger badder version of Pickett's Charge. That the Sounders only mustered a reply after they got back to their locker-room told the story. This was a massacre for the ages.

The Timbers have been historically slow starters in both games and seasons, but on this day, there was never any doubt. Portland came out throwing roundhouses. Seattle was always going to have to dig deep to stay afloat. Turns out, they wouldn't even get their hands up.

The warning signs flashed as early as the tenth minute for the Sounders, as an unmarked Liam Ridgewell went close at the back post off of Jack Jewsbury free kick. Just six minutes later, Seattle's amenable set piece defending would be taken advantage of by an unlikelier source β€” with Vytas heading home a corner to give Portland the lead.

It was only the beginning of what would become the most lopsided half ever played between the Timbers and Sounders in MLS.

Portland got plenty of tremendous performances, but this was Fanendo Adi's game. The striker, without a flight to catch this week, returned to the starting lineup with his usual vigor β€” and a special tenacity always reserved for match-ups against Chad Marshall and the Sounders.

Adi's presence β€” not to mention his territorial dominance β€” opened the game up immeasurably for the likes of Lucas Melano and Diego Valeri. The Timbers seemed to rejoice in having the big man back. The team, and the game, flowed around Adi.

The striker would get his goal just five minutes after Vytas opened his account, winning the battle to bundle home a rebound from a well-placed Valeri shot to make it two. If Adi does leave this winter, a major part of his legacy will be his terrorization of the Sounders. Adi has scored in every game he's played against Seattle at Providence Park.

The third goal came just before the half hour mark, with Lucas Melano tucking home a Diego Chara cross shortly after an excellent Stefan Frei save on Valeri. Number four would come from Steven Taylor, who, given the freedom of the stadium, would head past Frei to open his account on his MLS debut.

Craig Mitchelldyer/Portland Timbers

Seattle, to put it mildly, wasn't up for the fight. There were plenty of mitigating circumstances β€” the unsettling news about Clint Dempsey's health, a midweek match in Houston β€” but this was the wrong time to give a game away.

It was almost as if the Sounders took after the Emerald City Supporters and simply mailed it in. The number of simple mental errors that Seattle made was mind-boggling. The failure to launch on defensive set pieces was one thing, but the inability to execute the team's game-plan β€” which was to limit Portland's opportunities in transition and not give the ball away cheaply β€” was another story entirely.

Perhaps the Sounders were due for a letdown, but this is a loss that could cost the Sounders a playoff spot and Brian Schmetzer the full-time managerial position.

Seattle did mount a response at the beginning of the second half, as an unlucky deflection off of Steven Taylor β€” still fooling no one as a defender β€” made it 4-1 before a pretty Nicolas Lodeiro cross found Jordan Morris for 4-2. From there, though, the Timbers closed down shop.

The Sounders, true to form, didn't exactly go quietly. Lodeiro unveiled a Nigel de Jong impression midway through the first half with an awful lunge on Darlington Nagbe, and Nelson Valdez β€” MLS' single most pathetic player β€” threw the ball at a linesman. No one seemed to mind.

Portland's composure, on the other hand, matched its intensity. This was, save for a lackluster five minutes, an excellent performance.

One of the other key points was central midfield, where Portland's comprehensively outclassed Seattle. The result was less pressure on the Timbers' center backs, and more counter attacking opportunities, and much more of the game played in the Sounders' defensive third.

Jewsbury is enjoying his best run of form since last season's playoffs, and has, once again against the odds, made himself an integral part of the Timbers' fall plans. Chara, who picked up his first assist of the season on Melano's goal, played his best game of the summer.

And on this afternoon, once the Timbers got attackers running off Adi, the Sounders were left flapping in the wind.

The Timbers have backed themselves into corners plenty of times this year, but they've continually come out of those corners swinging. This is the biggest win of the season, and when Portland goes to Vancouver on the final day, they should be able to clinch both a playoff spot and the Cascadia Cup for the first time since 2012.

Portland has reignited its season in the most satisfying way possible. This game will be etched into Timbers-Sounders lore. The problem in 2016, though, hasn't been that the Timbers haven't been capable of great performances. It's been that they haven't been able to string them together.

Now's the hour. Portland clearly has the quality. The only way to do that first half justice? Finish the job. The Timbers have to keep Seattle out of the playoffs β€” and give themselves a chance to defend their crown.

Craig Mitchelldyer/Portland Timbers