Montreal Impact 1-0 New York Red Bulls
In Montreal, the Impact seizing a 1-0 victory over the New York Red Bulls thanks to Matteo Mancosu's stunning half-volley.
The Italian import out-raced two Red Bulls defenders and one-timed a blistering shot just inside the box to the left of keeper Luis Robles in the 61st minute.
Marco Donadel fed Mancosu with a well-timed long ball over the top of the Red Bulls midfield.
"Scoring the goal was an incredible feeling," Mancosu said. "We needed to find the breakthrough and there were a couple opportunities in the first half, but we didn't take them.
"We started the second half well, and then came this beautiful pass from Marco and I was able to hit it well toward goal. When you hit it well, there's nothing the goalie can do."
The visitors' best chance came in second-half stoppage time when Evan Bush parried a close-range shot by Omer Damari into the path of Bradley Wright-Phillips, who fired wide.
Damari was shown a red card seconds later for a late challenge on Calum Mallace, and won't be available for the return leg.
LA Galaxy 1-0 Colorado Rapids
Giovani dos Santos's second-half header was enough to give the Los Angeles Galaxy a 1-0 victory over the Colorado Rapids on Sunday and the edge in their MLS Cup playoff tie.
The Mexican striker made good use of a strong individual effort from Jelle Van Damme with a header that deflected off Rapids defender Axel Sjoberg and looped over Colorado keeper Tim Howard.
The Galaxy grabbed a slim lead in their Western Conference semi-final tie, which will conclude November 6 with a return leg in Colorado.
"It was very difficult," dos Santos said. "They press every single ball, and they're very compact. Not for nothing are they the best defensive team in MLS."
And Rapids coach Pablo Mastroeni was confident his team could overcome a one-goal deficit when they host the Galaxy at altitude in suburban Denver.
"We're in a really good spot," Mastroeni said. "I like our chances of getting a goal and going into the waning minutes or overtime at altitude, where teams struggle."
Toronto FC 2-0 NYCFC
In Toronto, goals from Jozy Altidore in the 84th and Tosaint Ricketts in injury time lifted the hosts to a 2-0 victory over New York City FC.
City, who were without Italian star Andrea Pirlo who is nursing a calf injury, created little offense and had to rely on newcomer Eirik Johansen in goal to thwart several strong Toronto opportunities in the first hour.
Seattle Sounders 3-0 FC Dallas
The biggest surprise of the night came in Seattle as the local side took a commanding 3-0 first leg after outclassing Oscar Parejas's FC Dallas team and current winners of the regular season Supporter's Shield.
An eight minute blitz which saw the Sounders bag three goals through Paraguayan Nelson Valdez and a Nicolas Lodeiro double give the Washington state team a significant advantage a head of Sunday's second leg.
“In the second half, in the first 20 minutes, Seattle outplayed us. We have to accept that,” Paerja said after the game. “Tonight we played against a very good team. That first 20 minutes they were very sharp. We allowed them to get in those spaces and score those goals.