Luciano Emilio became the league's first 20-goal scorer in five years and D.C. United extended its unbeaten streak to 11 matches with a victory over Toronto FC on Saturday in Washington.
Emilio, who leads the league with 20 goals, became the first MLS player to score 20 in a season since Los Angeles' Carlos Ruiz (24) and New England's Taylor Twellman (23) in 2002.
Christian Gomez's shot caromed off the crossbar and Emilio blasted home the rebound to cap the scoring in the 70th minute.
Jaime Moreno, the league's all-time leading goal scorer, tallied the 112th of his career and gave D.C. United a 3-1 lead in the 66th minute.
Fred took a nifty backpedal feed from Christian Gomez and scored from just outside the 18 with a blistering shot that bounced off the hands of sprawling Toronto FC goalkeeper Kenny Stamatopoulos for a 2-1 lead in the 57th minute.
Marc Burch's shot from 21 yards found the net and pulled D.C. United into a 1-1 tie in the 52nd minute.
Carl Robinson scored on a free kick to give Toronto an early 1-0 lead.
REVOLUTIONS 1, RAPIDS 0: At Foxborough, Mass., Khano Smith scored in the 88th minute to lift New England to its fourth win in its last six matches.
Smith scored his second goal of the season when he gathered a through ball from Shalrie Joseph, outran Colorado defenders down the side and beat Rapids goalie Bouna Coundoul.
New England (14-6-7) has already clinched a playoff spot.
Colorado (7-12-8) is now winless in its last five (0-3-2) and has scored just three goals in that span.