The reigning MLS Cup champions were down by three goals at halftime, a scoreline that held as D.C. took first place.
Fabian Espindola, Chris Rolfe and Perry Kitchen all found the net for the capital club in a torrid seven-minute spell in the first half, and Kansas City, and KC had no response to the offensive outburst.
"D.C. is good team," Vermes said after the match. "Give them credit, they made us pay and finished their chances. But we weren't good enough tonight. We knew what to expect from them, and at times we made it easy for them. We were sloppy in our distribution; we were caught out of position.
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"Like I said, we want the next game to come fast because this just isn't acceptable."
The former U.S. national team player refused to blame his team's heavy schedule for its breakdowns; KC played a CONCACAF Champions League match midweek.
"Absolutely not," he said. "D.C. was good on three counters, which our back four was absolutely horrendous on. It's one of those days where they came down on three routine plays and they scored three goals because of the way we were organized at the back. There has been a lot of credit given to our back four over a long period of time, but the way that they performed tonight, they're going to get the credit for giving up three goals.
"But this has nothing to do with playing against Real Estelí."