Toronto FC lost the second leg of its Eastern Conference semifinal second leg against New York Red Bulls 1-0, but still advanced on away goals as the tie ended 2-2 on aggregate.
Toronto came into the match holding a 2-1 advantage from the first leg in Harrison, New Jersey, with the two away goals giving Greg Vanney's team the upper hand from the off.
The hosts' best early chance came right before the 10-minute mark, when Jozy Altidore found space in the New York penalty area after a driving run, but hooked his low shot just wide of the far post.
Shorty after, a dangerous Victor Vazquez ball across the goalmouth was a boot-length away from finding Sebastian Giovinco at the back post before being poked to safety by Kemar Lawrence.
Toronto continued to have the better of the chances in the opening 45 minutes and had a penalty shout waved off after Giovinco was knocked down while in on goal after some neat build-up play from the Reds.
And Giovinco had one more chance before half-time after breaking free in the New York box and curling a close-range shot with the outside of his right foot wide of the far post when he looked likelier to score.
Altidore, Michael Bradley and Tyler Adams all saw yellow over the course of a testy first half that ended 0-0. Altidore received his caution for a tussle with Sacha Kljestan that spilled over into the tunnel as teams went back to the dressing room and both players were sent off before the start of the second half.
With both teams down 10 men, the Red Bulls got off to a dream start in the second half when Daniel Royer's shot from 40 yards took a deflection off Bradley Wright-Phillips and trickled into Toronto's goal giving New York an important away goal and a 1-0 lead.
Clinging to an aggregate lead on away goals, Toronto's nerves showed and Wright-Phillips should have made them pay when he was played into the area with a flick from Adams only to have his shot snuffed out by goalkeeper Alex Bono.
Toronto then thought they'd scored a decisive goal when Jonathan Osorio bundled home a Giovinco chip at the back post, but the referee waved off the goal and instead called a foul on the TFC player.
Vanney's team will face the Columbus Crew, who came out on top against New York City FC 4-3 on aggregate despite losing the second leg 2-0 at Yankee Stadium.
Trailing 4-1 on aggregate after the first leg in Columbus, Patrick Vieira's team got just the start it needed when Rodney Wallace was toppled in the penalty area by Frederic Brillant and David Villa slotted home the ensuing spot kick to make it 1-0.
There were nervy moments in the opening half for New York keeper Sean Johnson, a questionable punch fell to Federico Higuain in the area and a miscommunication with his defense almost saw a headed back pass find its way into his net.
Maxi Moralez's pinpoint cutback set Villa up just before half-time, but the Spaniard couldn't quite get a boot on pass before it was seemingly handled by Mohammed Abu in the area with no penalty given.
The host side clawed back one of the two goals it needed early in the second half when Crew defender Jonathan Mensah redirected Andraz Struna's shot into his own net to cut Columbus' aggregate lead to 4-3.
The chances came fast and furious after that for NYCFC, Moralez heading wide at the back post before Jack Harrison shot tamely at Zack Steffen in the Columbus goal and Wallace smashing one off the post from very close range.
Kekuta Manneh could have put it away just before the 90-minute mark, but his left-footed shot from close range smashed into the side netting to keep New York's hopes alive.
A flurry by NYCFC in stoppage time came up empty as the Crew hung on to eliminate the second-seed in the East and keep its MLS Cup dream alive.
The Houston Dynamo shocked the Portland Timbers in the Western Conference semifinals, beating the top seed 2-1 at Providence Park to advance to the conference finals against the Seattle Sounders.
Dairon Asprilla almost opened the scoring for Portland in the 23rd minute for Portland, but his powerful header was palmed away by Houston goalkeeper Joe Willis.
But the 25-year-old made no mistake on his second chance, smashing a volley following a corner into the Houston goal after defender Dylan Remick slipped and left Asprilla all alone.
Top-seed Portland's lead didn't last though as Remick made amends at the other end of the field by netting a golazo of his own to make it 1-1 and send the Dynamo to the dressing room with the upper hand in the tie on away goals.
Seeking a second that would really put Portland up against it, Erick Torres bombed down the middle of the field just before the hour mark and, with a good look at the goal, fired a well-hit shot well over the crossbar.
An air of desperation crept into the Portland side with 20 minutes remaining and the team poured forward looking for a critical go-ahead goal.
But the goal didn't come and instead Houston shocked the home crowd on the counter-attack when substitute Mauro Manotas picked up a pass from Eric Alexander and fired a shot past Jeff Attinella to give the visitors a 2-1 lead.
That meant Portland needed two goal to advance and Caleb Porter's team continued to push, but the deficit was too much to overcome and the Dynamo are on to the conference finals.
This is Houston's first trip to the conference finals since 2013, when it was still in the Eastern Conference.