An own goal after 30 minutes was enough for the home side as despite creating a host of chances at the RFK Stadium, we couldn't find an equaliser.
To make matters worse, the goal was a scrappy affair with Ben Olsen squirming past Christian Ziege and Ledley King before cutting it back for Hristo Stoitchkov who made somewhat of a hash of the chance only for it to deflect off Stephen Carr and trickle over the line with Kasey helpess.
"It was one of those difficult situations," reflected Kasey. "I would have easily saved the ball but at the same time, defenders aren't just going to lift their foot and let a shot go from eight yards out.
"It was a shame it had to just trickle into the net like that but that summed up the last few weeks defensively. It's been tough for the guys.
"We were disappointed at half-time with how we'd gone out in the first half but the second half we showed a little better.
"Give DC credit though. They approached it very professionally, worked hard and put us under a little pressure, first half especially.
"They were a credit to the MLS and I'm sure it won't be long before the league is getting more credit world wide."
Kasey Keller conceded it was typical our luck of late how we lost out to DC United in the Capital Cup on Wednesday night.