The 2014 first-round pick struck in the 24th minute when he uncorked a shot from 20 yards that found the back of Toronto's net. Mullins' strike canceled out a sixth-minute goal from Jackson, whose own long-distance effort took a slight deflection off of AJ Soares, catching keeper Bobby Shuttleworth flat-footed.
The match stayed level until the 83rd minute when Nguyen scored from the spot after Doneil Henry's arm got in the way of a shot from Mullins inside the area.
Shuttleworth was forced to make a leaping save on a header from Gilberto in the 87th minute to preserve the victory.
The 2-1 victory gives the Revolution (4-3-2, 14 points) their first win at BMO Field since Toronto (3-4-0, 9 points) entered the league in 2007. Meanwhile, Toronto remains in the loss column for the third straight match.
What it means: In a game that saw the guests look overmatched in the opening minutes, the Revolution eventually settled their nerves and stuck to their game following Jackson's sixth-minute strike. Mullins' goal was a thing of beauty, after he grabbed a pass from Daigo Kobayashi, ran at goal, and fired a shot that not even Julio Cesar could stop. The attacking fireworks quieted somewhat in the second half, but the Revolution never stopped pressing the issue, as evidenced by the sequence that led to Nguyen's strike from the spot. A draw would've been a favorable result for the Revolution, but to take away all three points at a venue they'd never won at is nothing short of remarkable.
Stat of the match: A well-stocked and finally healthy Toronto attack wasted no time making their presence felt in the opening moments, as they fired a total of five shots before the Revolution finally found their first in the 19th minute.
Bunbury back on the wing: For the second straight week, forward Teal Bunbury was assigned to the right side of the midfield. Bunbury started the Revolution's first eight games up top before last week's match against Sporting Kansas City. The move paid immediate dividends for the former first-round pick, as he went on to score his first goal of the season in the 92nd minute to lead the Revolution to a dramatic 2-0 victory over the defending champions.
Lineup changes: Mullins got his first start since First Kick, but this time he was slotted at up top in the Revolution's customary 4-1-4-1 formation. Mullins featured as the left sided midfielder in the Revolution's season-opening 4-0 loss to Houston, but was subbed off at halftime. Meanwhile, Kevin Alston, who missed last week's match due to red card suspension, reclaimed his spot at left back. An early injury forced Alston off the pitch, and last week's starter Chris Tierney came on to spell him.
Injury report: Center back Jose Goncalves (quad) and Kelyn Rowe (hamstring) did not make the game-day roster due as they continue to recover from injuries. Winger Saer Sene, who was excused from the club last week for personal reasons, was also unavailable due to a quad injury.
Next up: The Revolution will return to Gillette Stadium to face the Seattle Sounders next Sunday at 6 p.m. in a match that'll pit Clint Dempsey against the club that drafted him. Dempsey, who signed with Seattle last summer following a successful career in the English Premier League, spent three seasons in New England (2004-06) before he was transferred to Fulham in January 2007.