Los Angeles (AFP) – 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.

The Eastern Conference semi-finals got underway in Montreal, where Matteo Mancosu’s stunning half-volley lifted the Impact to a 1-0 first-leg victory over the New York Red Bulls.

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.

Mancosu has six goals in 16 appearances since arriving in July on loan from Serie A outfit Bologna, and has filled the void left by Ivorian star Didier Drogba who hasn’t played in a month as he battles a sore back.

“When you come up big against a good team like the Red Bulls, people start to talk,” said Montreal coach Mauro Biello, whose side will try to seal a conference finals berth in the return leg next Sunday. “His stock is rising.”

The Impact successfully stifled the Red Bulls’ potent attack.

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.

In other conference semi-final first-leg matches Sunday, Toronto hosted New York City FC in an Eastern Conference clash while in the West the Seattle Sounders hosted FC Dallas — winners of the Supporters’ Shield awarded to the team that tops the regular-season table.

Toronto are coming off a 3-1 victory over Philadelphia in the knockout round on Wednesday, their first MLS Cup playoff win, while City had a bye.

The Sounders advanced with a late winner on Thursday against Sporting Kansas City and will be out to avenge a penalty shootout defeat to Dallas in the same round of the playoffs last year.

While Dallas topped the table in the regular season, they could be vulnerable in the playoffs without playmaker Mauro Diaz, who is out with a torn Achilles tendon.