Sacha Kljestan and Lloyd Sam scored to help the New York Red Bulls beat the Montreal Impact 2-1 on Wednesday night.
New York will secure the Eastern Conference regular-season title with a win or draw in any of its three remaining matches. The Red Bulls are three points ahead of the LA Galaxy and FC Dallas in the race for the overall lead.
Ambroise Oyongo was shown a red card for a hand ball on what otherwise would certainly have been a goal by Bradley Wright-Phillips in the 15th minute, leaving Montreal a man down.
Kljestan put away the ensuing penalty.
Wright-Phillips slipped behind the defense on a breakaway, pulling goalkeeper Evan Bush out to the top of the box, but couldn't convert either of two shots. The second, however, ricocheted back to Sam, who chipped over a scrambling Bush to make it 2-0 going into the half.
Didier Drogba converted a penalty in the 67th minute for Montreal.
Meanwhile in Vancouver, the Whitecaps drew 0-0 with FC Dallas to clinch a playoff spot for the second straight season.
Vancouver is third in the Western Conference, a point behind FC Dallas and the LA Galaxy.
Dallas had the best chance to win the match, but substitute Blaz Perez's shot in the 90th minute slipped just wide of goalkeeper David Ousted's far post.