MONTREAL -- The Montreal Impact built a three-goal lead and then barely hung on for a 3-2 victory over Toronto FC in a wild opening game of their MLS Eastern Conference final that was delayed 30 minutes by a groundskeeping error on Tuesday night.

Dominic Oduro, Matteo Mancosu and Ambroise Oyongo put Montreal in front in the opening 53 minutes, but Jozy Altidore and Michael Bradley answered back with goals before a roaring sellout crowd of 61,004 at Olympic Stadium.

While Montreal will take a lead into the second leg of the two-game, total goals series on Nov. 22 at BMO Field, Toronto picked up two all-important away goals that can serve as the tiebreaker. A 1-0 or 2-1 TFC win in the second leg at home would win Toronto the series.

Montreal looked well on its way to crushing TFC in a playoff match for a second year in a row, having beaten their closest rival 3-0 in the single-game knockout round in October, 2015 -- a result Toronto players vowed to avenge.

The match got off to an embarrassing start for the home side as the lines for the 18-yard boxes were too narrow and had to be repainted before the game could begin. Fans cheered as each new line was drawn.

They got louder as Montreal used two quick attacks against the flat-looking TFC to take the lead.

In the 10th minute, Hassoun Camara fed the ball ahead to Patrice Bernier, who slipped it past defender Nick Hagglund to send Oduro in alone on the right side. Oduro fired a low shot inside the far post for his first of the playoffs.

Two minutes later, Oduro intercepted a Steven Beitashour pass and lofted it to Ignacio Piatti on the left wing. The Argentine put a hard pass into the box, where Mancosu stepped in front of a defender to redirect the ball past goalie Clint Irwin.

In the 53rd, Oyongo striped the ball from Sebastian Giovinco near he halfway line and took it in on a solo run the edge of the Toronto box, cut left and shot across his body inside the right post.

With Montreal still in control a few minutes later, TFC coach Greg Vanney substituted midfielders Jonathan Osario and Armando Cooper with forward Tosaint Ricketts and midfielder Will Johnson. It looked to give his side a spark.

In the 69th, Tosaint put a ball off the post, but Beitashour got it to Altidore for a header from close range.

Four minutes later TFC was again buzzing inside the Montreal box. Altidore looked to push defender Victor Cabrera to the ground to open up space to slip a pass to Ricketts, who fed Bradley for a shot from directly in front.

Toronto reached the conference final with a convincing 7-0 aggregate win over second-place New York City, while Montreal upset the top-seeded New York Red Bulls 3-1. Both are farther into the playoffs than they've ever been before.

With last week's FIFA international break, it had been 16 days since either team last played a match.