Alvaro Saborio scored twice to lead RSL past Michael Bradley, Jermain Defoe and Toronto FC.
Alvaro Saborio got the scoring going early from the spot after he was pulled down in the box by Doneil Henry.
Luis Gil made it 2-0 before the half-hour mark, curling home with his left foot from just inside the box to double the lead.
Saborio made it 3-0 in the 55th, taking a clever chip in over Julio Cesar to round out the scoring.
The win was Salt Lake's first of the year and it handed TFC its first loss of the season.