WASHINGTON -- Twelve years ago, D.C. United won their second consecutive MLS Cup with a 2-1 triumph against the Colorado Rapids at RFK Stadium as 57,431 devoted fans braved cold, rainy conditions to watch their team win a championship on home turf.Twelve months ago, United secured another trophy in their friendly confines, capturing their second-ever U.S. Open Cup title with a 2-1 victory against the Charleston Battery at RFK.But when it came time to defend their cup and add another chapter to that proud history on Wednesday night, D.C. saw the roles reversed in crushing fashion.Playing with pace, discipline and attacking intent, Seattle Sounders FC stunned RFK's raucous faithful with a 2-1 win that provided the first tangible fruits of a delirious debut season in the Emerald City -- and aptly capped a cantankerous leadup that made it one of the most absorbing U.S. Open Cup final matchups in the 96-year-old tournament's existence."It's tough when you lose at home," said D.C. midfielder Santino Quaranta, whose team has now lost two consecutive matches at RFK after going undefeated in their first 13 games at the venerable facility this season. "But when you lose a cup final like this at home, it's even worse."United were eager to rouse their fans for the occasion after Seattle general manager Adrian Hanauer traded barbs with D.C. president Kevin Payne regarding U.S. Soccer's site selection for the final last month, and the Black-and-Red's supporters duly delivered a passionate display of noise and color while a surprising number of Sounders FC supporters made the long journey from the Pacific Northwest.That playoff-type ambiance helped inspire an up-tempo, free-flowing game with plenty of chances at either end. On balance Seattle looked more dangerous going forward, finding gaps in United's 3-5-2 formation while D.C.'s strike force looked blunt around goal despite plenty of possession."We were attacking, but in that final third we couldn't string any good passes together for Luciano [Emilio] or Jaime [Moreno] to have clear opportunities and obviously that was a determining factor," said playmaker Christian Gomez.United were kept in contention by some quality goalkeeping from Josh Wicks, who carried his team with four excellent saves in the first half only to go from hero to goat in a flash as he impetuously stomped on Fredy Montero after the Colombian had netted the opening goal in the 67th minute.Referee Alex Prus was alerted to the incident by fourth official Andrew Chapin and the resulting red card sentenced United to finish the night a man short."It was a mistake on my part and I've got to learn my lesson," said Wicks afterward, the most downcast face in a somber United locker room. "The fourth official made a call and the ref made the final decision. That was it. I've got no excuses for it."Wicks' mates fought valiantly, testing the Sounders FC back line with overdue urgency even after surrendering a second goal at the hands of Roger Levesque. A late goal from Clyde Simms renewed RFK's hopes -- and decibels -- but the home side's desperate, final push came up short and they were left to rue what might have been."To his credit, Josh kept us in there and then Josh makes a mistake that costs us in the end," said D.C. coach Tom Soehn afterwards. "He's got to be smarter than that. ... Actually when they got their goal I thought we were getting the momentum our way. It was discouraging to [concede] the goal and I feel like if we would've had 11 men on the field we still could've impacted that game better."United had to suffer the indignity of watching Seattle hoist the trophy on their home field, but despite the ample pregame sniping between the clubs' fans, Soehn and his charges accepted their setback with grace."We gave up way too many chances -- they could've had four or five goals," said Quaranta. "I thought we fought back after we went down a man, but in the end we didn't deserve to win tonight."