The hosts, who dominated the match from start to finish, broke the deadlock on 27 minutes when Kei Kamara planted a powerful header into the top left corner of the net from 12 yards.
Kamara doubled his side's lead early in the second half with a similar effort following a Soony Saad cross.
Dimitry Imbongo Boele was sent off for collecting his second yellow card of the night on 65 minutes.
Substitute Andy Dorman then followed Boele down the tunnel on 86 minutes after he was shown a straight red for a rash tackle on Kamara.
Benny Feilhaber scored with a precise free kick to add a third goal for Kansas in stoppage time.