The visitors took the lead in the 21st minute when a loose ball fell to Jose Mari 30 yards from goal and let fly with a vicious volley that flew into the bottom corner of the net.
Salt Lake were not behind for long as they equalised when Ned Grabavoy cleverly back-heeled a pass into the path of Joao Plata. The striker then finished in style as he blasted the ball into the top corner.
The home side extended their advantage when Nasco failed to handle a free kick from Morales and he parried the ball straight into the path of Chris Schuler, who prodded the ball over the line with his hip.
Nasco's evening got even worse when Salt Lake scored their fourth goal as Plata and Morales combined in a neat one-two inside the area. The striker's effort from close range hit the foot of the keeper and rolled into the net.
In the second half, the home side seemed content to sit on their lead but yet another error from Nasco handed them another goal.
The keeper came through a crowd of players to try to claim Morales's corner, but he dropped the ball at the feet of Carlos Salcedo, who slotted the ball home to secure his side's victory.