Seattle Sounders became the second MLS team to clinch a play-off berth with their 4-1 rout of Vancouver Whitecaps on Saturday. 

Seattle are atop the Western Conference on 57 points, second only to runaway Eastern Conference leaders and Supporters' Shield pacesetters New England Revolution (65), who already have secured the top seed on their side. 

The Sounders established themselves early with goals from Shane O'Neill in the fifth minute and Nicolas Benezet in the 14th at home to the Whitecaps amid their 13-game winless run against Seattle – the club's longest drought against any opponent in MLS.

After Vancouver clawed a goal back via Brian White at the end of the first half, Will Bruin added a third for Seattle 10 minutes into the second period and Leo Chu netted in the 90th minute to close it out. 

New York Red Bulls kept their play-off hopes alive, defeating slumping Inter Miami 1-0 behind a 25th-minute goal courtesy of Patryk Klimala. 

The Red Bulls sit ninth in the east, three points adrift of Montreal, rivals New York City and DC United, who currently hold the final three post-season positions.

Inter Miami are eight points off the pace amid a five-match losing streak.

FC Cincinnati became the first team officially eliminated from play-off contention following a 2-1 home defeat to third-placed Philadelphia Union. 

Though Philadelphia had possession for only 37 per cent of the match, they built a lead through Kacper Przybylko in first-half stoppage time before Paxten Aaronson doubled the advantage 11 minutes into the second half.

Haris Medunjanin netted in the 82nd minute but it was too late as Cincinnati suffered their 16th loss of the season against eight draws and an MLS-worst four wins.