Sporting Kansas City won through to the Western Conference semi-finals after accounting for Vancouver Whitecaps 3-1 in the MLS Cup play-offs.

Khiry Shelton, Nicolas Isimat-Mirin and Graham Zusi scored as Sporting KC earned a showdown with either Seattle Sounders or Real Salt Lake.

Sporting KC entered Saturday's play-off with three straight defeats. The three previous times they lost their last regular-season match before the post-season, the club were eliminated in their first play-off tie (1997, 2014, 2017).

But Sporting KC defied that record thanks to their performance at Children's Mercy Park, where Shelton opened the scoring in the 17th minute.

The Whitecaps – who had won just one of their nine games away to Sporting KC, dating back to September 2017 – equalised via Cristian Dajome's 39th-minute penalty.

Sporting KC, however, restored their advantage when Isimat-Mirin struck in the third minute of first-half stoppage time and Zusi sealed the victory 13 minutes into the second period.

In the Eastern Conference, Philadelphia Union booked their spot in the semi-finals thanks to a last-gasp 1-0 win against New York Red Bulls after extra time.

Jakob Glesnes' thunderous and dramatic volley in the 123rd minute sent the Union through to the next round of the play-offs.

The Red Bulls had lost only one of their last 12 matches (W7 D4) en route to qualifying for their 12th straight postseason – the second-longest streak in MLS history (Sounders 13 in a row, 2009-present). The 25 points the Red Bulls also collected since September 17 were the most in MLS in that span.

Next up for the Union is a meeting with either Orlando City or Nashville.

Jakob Glesnes scored a sensational stoppage-time equaliser as Philadelphia Union came from two goals down to secure a 2-2 draw with Atlanta United on Sunday. 

Anthony Fontana and Kacper Przybylko were denied by Brad Guzan as Philadelphia looked more likely to find the breakthrough in the first half of the Eastern Conference clash at the Mercedes-Benz Stadium. 

It was Atlanta who opened the scoring, though, the unfortunate Przybylko heading into his own net from a corner shortly before the hour. 

Anton Walkes looked like he had secured three points for his side with a powerful header seven minutes from full-time, but the visitors had other ideas. 

Cory Burke pulled one back a minute later with a close-range finish before Glesnes sealed a share of the spoils with a stunning drive from 30-yards that crashed in off the underside of the crossbar.