The Brazilian forward stepped up to the penalty spot in the 43rd minute after Kekuta Manneh was brought down in the area and blasted a shot past Colorado goalkeeper Clint Irwin.
He then danced around a Rapids defender in the 74th minute to tie Mike Magee of the Chicago Fire for the MLS lead in goals with 21. That strike gave Sanvezzo the league's Golden Boot award because he has more assists than Magee.
But not wanting to leave any doubt, the 25-year-old completed the hat trick in the 85th minute after taking a through ball and one-touching a shot past a helpless Irwin. Sanvezzo, who took off his jersey to celebrate, almost had his third just moments earlier, but saw his effort cleared off the line.
After his first goal, Sanvezzo presented the ball to veteran Whitecaps defender Young-Pyo Lee. The match at B.C. Place Stadium marked the final game for the 36-year-old South Korean, who participated in three World Cups and had a long club career in Asia and Europe before joining Vancouver in 2011.
The Whitecaps (13-12-9) saw their post-season hopes crushed eight days earlier when the Rapids (14-11-9) defeated Vancouver 3-2 in Commerce City, Colo. Last season, the Whitecaps became the first Canadian team to make the MLS playoffs.
Leading 1-0 after half-time, Sanvezzo had a chance to double Vancouver's lead in the 48th minute, but his free kick from the left sailed harmlessly over the net.
Darren Mattocks had a partial breakaway seconds after entering the game as a substitute, but his shot sliced wide of Irwin's goal in the 61st.
Vancouver defender Sam Adekugbe, 18, made the first professional start of his career and saved a goal three minutes later by clearing the ball away from Edson Buddle after a stop by Whitecaps goalkeeper David Ousted.
Colorado Deshorn Brown had a free header in front of Ousted in the 73rd before Sanvezzo doubled Vancouver's lead with another moment of brilliance.
He almost completed the hat trick in the 83rd minute, but his shot was cleared off the line.
Lee was then substituted in stoppage time to a rousing ovation from both fans and players.
Sanvezzo was a man possessed all game and his first chance came in the 11th minute when he forced Irwin into a diving save to his right. The Colorado goalkeeper then made another stop three minutes later when Vancouver defender Brad Rusin got his head to Sanvezzo's corner.
The Rapids' best chance of the first half came in the 30th minute when Gabriel Torres, who scored twice against the Whitecaps last weekend, fired a shot that Ousted pushed to his right. The ball fell into the path of an onrushing Colorado player, but Rusin and Ousted combined to keep the ball out.
Sanvezzo scuffed a shot in the 37th minute, but wouldn't be denied on his penalty kick six minutes later.
Note: Prior to the games, the Whitecaps held a video tribute for Lee and also unfurled a South Korean flag in the crowd. Lee, who is expected to join the Whitecaps front office, had his name chanted by the crowd throughout the game.