WASHINGTON -- D.C. United were unbeatable in league matches at RFK Stadium for the first six months of the 2009 campaign, racking up six wins and five draws and allowing just eight goals over some 900 minutes of play.But over the last two weeks, with their pursuit of the postseason necessitating constant focus and accrual of maximum points at all costs, the Black-and-Red have stumbled badly in the friendly confines, suffering two consecutive losses to leave themselves in a precarious position as the MLS regular season enters its final stages.Following a 2-1 setback at the hands of Seattle Sounders FC two Saturdays ago, United's latest slip-up arrived courtesy of the San Jose Earthquakes on Sunday afternoon as D.C. failed to make the most of a dominant first-half display and paid a severe price, dropping another 2-1 result that left the team, and their home fans, bitterly disappointed."It's devastating. But in the end, we didn't finish the game off," said midfielder Santino Quaranta. "I think the game came so easy to us the first 40 minutes of the first half that I think we thought we were just going to go out and keep doing what we were doing. It seemed like they didn't touch the ball in the first half -- we did whatever we wanted."United began the weekend with a precarious hold on one of the league's final playoff berths while the Earthquakes remained stuck in the Western Conference cellar with little left to play for except pride, professionalism and hopes of a roster spot next season. As Quaranta noted, the first 40 minutes of the contest reflected those differing fortunes as D.C. bossed the game and carved open their opponents time after time."Obviously it's thoroughly disappointing," said United head coach Tom Soehn. "We had every opportunity to run away with the game in the first half and we were unable to put our chances away. And any team you keep around, it's going to come back and haunt you."One United defender summed it up even more succinctly."We let them hang around a little too long," said right back Lawson Vaughn.After weathering that fierce first-half onslaught, San Jose rallied superbly down the stretch and displayed the sort of opportunism that would serve D.C. well at the moment, snaring two unanswered goals in the final 33 minutes as Ramon Sanchez and Ryan Johnson made the most of a set piece and a goalmouth scramble, respectively."It was a game we needed to win. I think it was a game we should've won," said D.C. goalkeeper Josh Wicks. "But you have a team that's playing hard defensively and doing what they have to do, players making saves and stuff -- team gets two chances and scores. That's pretty much all I can say."Wicks left the game five minutes into the second half after separating his shoulder in a collision with Johnson and his status remains uncertain. The netminder has an MRI scheduled for Monday and though he described the initial injury as "the worst pain in my life," he could return to action this week, pending further diagnosis."The [medical staff] said if it feels good when I wake up in the morning, I can do a little training," he explained. "It's just day by day."The same could be said for his club's playoff prospects. United will likely have to run the table in their three remaining league matches (vs. Chivas USA and Columbus at RFK, then the season finale at Kansas City) to assure themselves of a spot in the postseason."We've put ourselves in a bad spot by slipping two home games," said Soehn. "We've talked about this home stretch but talking about it means nothing if you don't finish through and get your points. So we've let ourselves down and we've got to find a way out of it."