A composed 3-0 win over the Impact saw the capital club open up a two-point lead over rival New York in the Eastern Conference.
The first half looked like it would end scoreless until Chris Pontius picked up a pass from Dwayne De Rosario in midfield. The United forward dribbled past the Montreal back line and finished with a hard shot into the far post.
Robbie Russell doubled D.C's lead soon after the restart, diving to meet a perfectly curled free kick from Branko Boskovic. Hamdi Salihi put the game beyond doubt in stoppage, following up a spilled save on a shot from Nick DeLeon.
The win puts D.C. top of the East again with 33 points, after New York's draw against Toronto briefly saw the Red Bulls take pole position by a single point.
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