Vancouver (2-2-4) tied it on Fernandez's 35-yard shot in the 94th minute.
Joao Plata and Alvaro Saborio scored in the first nine minutes for Salt Lake (3-0-5), the only unbeaten team in MLS team and the ninth team in league history to go undefeated in its first eight games. Salt Lake has a 12-game regular-season unbeaten streak.
Salt Lake brought a fully healthy Plata back into the starting lineup for the first time in four games. It offered a major spark to the team's offence in the opening minutes.
Plata put RSL on the board in the second minute in spectacular fashion. With only Vancouver goalkeeper David Ousted to beat, Plata fired the ball and threaded it inside the far post from the opposite side of the box.
Salt Lake took a 2-0 lead in the ninth minute on Saborio's goal. Ned Grabavoy drew three Whitecaps' defenders to him as he dribbled through traffic. It allowed Grabavoy to lay the ball off to an unmarked Saborio just outside the 6-yard box. Saborio curled the ball inside the near post for an easy goal.
RSL kept Vancouver off the board until the waning minutes of the second half. The Whitecaps avoided the shutout with Mezquida's goal in the 86th minute. Nick Rimando uncharacteristically fumbled the ball on a save. Mezquida got his toe on the ball in front of Rimando and popped it over his head and into the net.
The goal prevented Rimando from notching his 112th career regular-season shutout and moving into a tie with MLS leader Kevin Hartman. More importantly for Vancouver, it paved the way for Fernandez to steal a point in the final seconds.