Updated

Dwayne De Rosario made up for his midweek penalty miss, which cost D.C. United a win against Chivas USA, on Saturday.

De Rosario scored a hat trick and assisted on a fourth goal in just more than 30 minutes, as D.C. United snapped Real Salt Lake's five-match win streak with a 4-1 victory at RFK Stadium.

Andy Najar opened the scoring in the 13th minute off an assist from De Rosario and the Canadian international followed with goals in the 22nd, 27th and 31st, as he took over the scoring lead in Major League Soccer.

De Rosario has 13 goals this year, 10 with United, two with Red Bull New York, and one with Toronto FC, where he started the season. He also scored Wednesday against Chivas, but missed a penalty in stoppage time of a 2-2 draw.

He responded to the mistake with an impressive performance as he sent a pin- point, cross-field pass to Najar early in the match and the 2010 MLS Rookie of the Year settled with one touch, then fired past RSL goalie Nick Rimando.

De Rosario added a second goal for United less than 10 minutes later, as Najar returned the favor with a pin-point pass from the right, and De Rosario headed past Rimando from 8 yards.

His assist was his 11th of the year, which leaves him just three behind David Beckham of the Los Angeles Galaxy and Brad Davis of the Houston Dynamo for the MLS lead.

United's hitman added his second goal in the 27th when a fortunate bounce gave Josh Wolff possession near the edge of the penalty area, and he slipped a pass back to De Rosario to send first-time shot into the top right from 22 yards.

D.C. (9-8-11) sealed the win just after the half-hour mark when De Rosario hit a free kick from 30 yards into the upper-left corner, again leaving Rimando no chance, to complete his hat trick.

Alvaro Saborio scored his 10th goal of the season in the 86th as RSL avoided a shutout.

United won for just the fourth time at home all season, but used the effort to improve its postseason chances, as well as stay in contention for the Eastern Conference title one year after finishing with the worst record in MLS.

RSL (15-8-6) lost ground on Western Conference leader Los Angeles and its hope of a Supporters' Shield - given to the team with the top record in the regular season - likely slipped away. L.A. leads Real by 10 points.