Chester, PA (SportsNetwork.com) - A pair of heated Eastern Conference rivals will tangle on Sunday when the Philadelphia Union welcome D.C. United to PPL Park.

It's a tale of two sides heading in opposite directions as United comes into the clash in first place in the East and riding an eight-game unbeaten streak, while Philadelphia has struggled to get its season on track and has just one win through its first 11 matches.

United will be on short rest after claiming a 2-1 victory over Orlando City on home soil on Wednesday.

United fell behind against the expansion Lions after 11 minutes when Aurelien Collin ripped a strike on target that was deflected and allowed rookie Cyle Larin to knock it home.

But United responded with second-half goals from Kofi Opare and Chris Rolfe to steal all three points from Orlando late on for a second time this season.

"It was a little lethargic in the first half. I think there was a bit of a fortunate bounce with their goal, but give the kid credit, it was a very good finish," said United head coach Ben Olsen.

"We were off in some of the final stuff and the class that I thought we had in the second half. I think we just took care of the ball a little bit more. We were patient, but urgent, in the way we broke them down and I thought it was a very good second half. I thought the substitutes brought what we need subs to bring. Chris Rolfe brings his class, Miguel Aguilar brought energy and a youthful feistiness that the game needed and Jairo Arrieta comes in and makes a wonderful pass to Rolfe. Overall, we are happy with the points and now we have to turn around and go to Philadelphia."

Philadelphia, meanwhile, has struggled mightily all season and come into the match with just one win following a 3-0 shellacking at the hands of Vancouver Whitecaps FC.

The home side opened the scoring in the 32nd minute as youngster Cristian Techera did well to chip the ball into space for Morales, who took a touch and lofted it over out-of-position Union goalkeeper Brian Sylvestre.

It was 2-0 for the 'Caps one minute before the break when Cristian Maidana put the Union in a difficult spot with a poor back pass and Rivero outmuscled Philadelphia defender Ethan White, went in alone and easily slotted it past Sylvestre.

Philadelphia made several attack-minded substitutions in the second half hoping to find an offensive spark, including sending forward Conor Casey onto the field in place of White in the 76th minute, but the Union remained largely toothless at the offensive end of the field.

Things then got even worse for the visitors when rookie defender Richie Marquez was shown a straight red card by referee Ismail Elfath for a late challenge in the 78th minute.

Vancouver then put an exclamation point on the performance with nine minutes to play when Mattocks blasted one past Sylvestre for his third goal of the season to wrap up all three points.

"I thought after a decent first 30 minutes, we should have gone up 1-0," head coach Jim Curtin said. "David Ousted made a great save. I think Andrew could've received it a little bit better but I think it deflected off his shin. If you don't take your chances against a very good team, you're going to get punished."