Kyle Beckerman scored the visitors' only goal.
Sealy lit up the scoreboard just 36 seconds into the match as Rapids goalkeeper Joe Cannon parried Alex Zotinca's shot into the path of the Trinidad and Tobago national team player, who finished the job.
It was the second-fastest goal in Wizards history after Arnaud's strike 33 seconds in against the Rapids Aug. 22, 2003.
Colorado retaliated 10 minutes later to knot the affair 1-1.
The Wizards then broke the deadlock in the second half, scoring two goals in three minutes, first by Van den Bergh in the 54th minute and then by Arnoud moments later.
Arnaud scored again in the 77th minute.