Salt Lake (13-6-10) swept the three-game series with Colorado (8-14-7) to earn the Rocky Mountain Cup trophy.
Salt Lake trailed 1-0, but responded with three goals in five minutes.
Plata sent a well-placed ball into the upper right corner in the 32nd minute off a backheel pass by Ned Grabavoy. Salt Lake added a corner kick goal a minute later and Chris Schuler cleaned up a free kick in the 37th. Real got an own goal by Colorado goalkeeper Joe Nasco in the 45th. In the second half, Carlos Salcedo capitalized on a failed clearance in the 63rd.
Colorado's Jose Mari rolled in a shot from distance in the 21st minute, catching goalkeeper Nick Rimando off-guard. The Rapids' Nick LaBrocca was suspended for one game and fined an undisclosed amount by MLS prior to the game.