D.C. United 3, Chivas USA 0

D.C. United has been MLS's best team the last month. Chivas USA has been the league's worst for 41/2 months. So it came as no surprise that United maintained its run of excellence at RFK Stadium yesterday with a 3-0 victory over the awful expansion club, extending its winning streak to four and its unbeaten stretch to six.

However, it took extreme patience on a smoldering afternoon before 16,169 fans for United to take the lead and restore order in what began as a mammoth mismatch.

The striking duo of Santino Quaranta and Jamil Walker scored two minutes apart just before halftime and Dema Kovalenko added his third goal in the last three matches during a sleepy second half as United (11-6-5) continued its ascent in the Eastern Conference standings with 10 games left.

"The toughest part is always to keep focus and concentrate," Coach Peter Nowak said. "In a game like that, Chivas has nothing to lose. . . . As I told my guys, 'You have to be very careful going forward, but in this weather condition, if you have a chance, you have to put it in.' We did a pretty good job in the two minutes or five minutes we scored two goals, and actually the game was over."

Goalkeeper Nick Rimando and his defensive corps, rarely bothered by Chivas's rudderless attack, registered their league-best 10th shutout. Chivas (3-17-3) lost its third straight as it heads toward one of the worst single-season performances in MLS's 10-year history.

It took a long time for United to break down Chivas's packed formation, however. The heat forced a slower and slower pace, and play became painfully deliberate as the half unfolded. Walker, starting because of injuries to Freddy Adu and Alecko Eskandarian and a suspension to Jaime Moreno, failed on two clear bids in the box. Chivas created marginal chances of its own, but wasn't very menacing in the penalty area.

Just before the break, United turned the match.

It started in the back, where Bobby Boswell stepped up and took possession on the run in midfield. He played a give and go with Christian Gomez, receiving the ball between defenders as he charged into the penalty area. With a pinpoint cross, Boswell found Quaranta, who easily deposited the shot -- and his tumbling self -- into the net for his third goal of the year.

"I saw a huge gap and normally I wouldn't have made that run, but I just wanted to give [Gomez] another option, and he found me," said Boswell, who is making a serious push for MLS rookie of the year. "I saw Santino breaking through and I just put it out there for the finish."

Two minutes later, Kovalenko slipped an outstanding diagonal pass to Walker, who ran away from defender Douglas Sequeira, took one touch and placed a 10-yard shot into the lower left corner for his first regular season goal since late 2003.

"We were a little bit frustrated because we weren't finishing the chances, but as long as they weren't scoring and we kept on creating, we were all fine with it," Walker said. "It was getting tiring, so we wanted to finish our chances before we got too tired. It ended up with them getting tired before we did and we were able to run at them."

United controlled the second half and, at several points, linked about a dozen passes together, drawing shouts of ole! from the appreciative crowd. Chivas mounted no challenge whatsoever, wilting in the heat and under United's confident play.

Any chances of a United letdown were put to rest in the 64th minute when Walker flicked Bryan Namoff's long ball into Kovalenko's charging path for a clear run and a composed finish to the far corner.

"Early in the season we weren't getting the results we deserved," Boswell said. "Now it's starting to go the other way and we're starting to win games."

United Notes: Midfielder Ben Olsen left in the 27th minute with a strained oblique muscle. He is day-to-day. . . . United will play an exhibition Tuesday at minor league Harrisburg (Pa.). where Josh Gros and Olsen grew up, before hosting Los Angeles on Saturday.