Toronto (9-10-6, 33 points) remained just ahead of Orlando City (8-11-6, 30 points) as both try to make their way above the playoff line in the Eastern Conference.
It was the first time in five all-time games in Toronto that the Lions came away with a point. The Reds won the previous four meetings by a combined score of 13-3.
Orlando City's Michel opened the scoring in the 69th minute, just a minute after entering the match. Teammate Dom Dwyer started a three-on-three break near midfield, passing the ball out wide to the right wing to Chris Mueller.
Michel trailed the play and took a cross from Mueller at the top of the 18-yard box on the far side of the field, dribbled to within 8 yards and put a shot into the lower right corner of the net as Reds goalkeeper Quentin Westberg stuck out his left leg in attempt for a kick save.
Michel was called for a foul on the Reds' Richie Laryea in the 74th minute, with referee Kevin Stott pointing to the penalty spot. But after a video review, it was ruled the foul occurred just outside the penalty area on the right wing.
Toronto's free kick by Alejandro Pozuelo, which came in the 77th minute, went to Michael Bradley at the top of the 18-yard box, but his low shot was blocked by Lions defender Kyle Smith. The ball ricocheted off Orlando City teammate Robin Jansson and right Mullins, who had entered four minutes earlier.
His one-timer from just outside the top of the six-yard box found the back of the net for his first goal with the Reds since being acquired from Columbus on July 11.
Lions goalkeeper Brian Rowe made four saves while Westberg had one.