But when the final whistle was blown last fall, United had come into Rio Tinto Stadium and escaped with a 1-0 victory and the trophy RSL desperately wanted.
But when the two teams meet Saturday for the first time since October, RSL defender Nat Borchers insists revenge won't be on anyone's mind. In fact, without the jerseys, it would be hard to recognize the club from a season ago.
"They're a different team," Borchers said this week, before joking that "the only guy I really want to go studs up on is Lewis Neal for scoring that game-winner on us in Open Cup."
D.C. has indeed been remade.
In 2013, United won three league games (with one of them coming early in the year against RSL). Its 16 total points were the worst in the league by a double-digit margin.
But an influx of veteran talent has helped D.C. coach Ben Olsen turn things around. Coming into Saturday night, D.C. seems playoffs-bound, with 37 points in hand.
"They're a much more dynamic team and much more defensively cohesive," Borchers said. "They've brought in some guys who have done very well for their group."
Defender Bobby Boswell was imported from Houston, and the team's attack was beefed up with the additions of former RSL striker Fabian Espindola United's leading scorer this year and former Seattle Sounder Eddie Johnson.
RSL captain Kyle Beckerman is hoping a revamped lineup will mean a revamped style of play come Saturday.
"Last year, that's all they had to play for was the Open Cup final," Beckerman said. "So I'm hoping that they'll come out and play us. Last year they were limited with what they could do, and realized [they] were just going to have to defend and see if [they] could nick a goal. And that's what happened and credit to them, they won the game. We're hoping they come out [and play this time]. They're a better team this year."
RSL, meanwhile, will be without two starters. Full backs Chris Wingert and Tony Beltran are each serving a one-game suspension for yellow card accumulation.
But coach Jeff Cassar said his team should be ready for a familiar foe.
"I think the guys are going to be up for this game, for many reasons," Cassar said. "First and foremost, three points at home is critical. It's tight in the West right now. Even though we have a fantastic record, we're not far out of being out of the playoffs. On top of that, it's against a team that we lost to in the Open Cup final. I'm sure there are going to be a lot of ill feelings inside the guys."
D.C. Unitedat RSL
O At Rio Tinto Stadium, Sandy
Kickoff • Saturday, 8 p.m.
TV • Ch. 4
Radio • 700 AM
Records • RSL 9-4-9 (36 points); DC 11-6-4 (37 points)
Last meeting • D.C. United, 1-0 (U.S. Open Cup final, Oct. 1, 2013)