WASHINGTON (AP) -- Chris Pontius scored at the 45-minute mark of the first half and Robbie Russell and Hamdi Salihi added second-half goals and DC United blanked the Montreal Impact 3-0 Saturday night.
United (10-5-3) took sole possession of first place in the Eastern Conference with 33 points as the New York Red Bulls (9-4-4) played to a 1-1 draw against Toronto.
United have won 6 of 8 overall and are unbeaten in their past nine home games.
The expansion Impact (5-10-3) managed just one shot on goal. Montreal has dropped 5 of 7 and is 1-8-1 in road games.
The teams appeared headed to halftime scoreless when Pontius took a pass from Dwayne De Rosario about 35 yards out.
Pontius started to his right just outside the box, quickly cut back to his left around a defender and beat goalkeeper Evan Bush to the far side for his ninth goal of the season.
It was De Rosario's league-leading 10th assist.
Bush was making his first appearance of the season in place of Montreal's regular goalkeeper, Donovan Ricketts, who started the team's first 17 games.
In the 50th minute, Robbie Russell scored his first goal of the year on a header from the center of the box off a free kick by Branko Boskovic.
Salihi closed the scoring, netting his fifth goal when he banged home a rebound off an Evans' save during injury time.
Both teams had good scoring chances early.
In the 11th minute, Montreal's Sanna Nyassi unloaded from outside the box and United's Bill Hamid was forced to make a diving deflection.
Bush returned the favor with a leaping deflection on a shot from about 40 yards by Maicon Santos in the 20th minute.
A season-high RFK crowd of 18,302 turned out despite the 92-degree temperature at kickoff.