Dominic Oduro scored in the 93rd minute as the first-place Montreal Impact rallied back from a three-goal deficit to draw 4-4 with Columbus Crew SC on Saturday night.
Kei Kamara opened the scoring in the 16th minute for Columbus after heading home Justin Meram's cross, but Ignacio Piatti tied it at 1-1 in the 26th minute from a curled shot.
Kamara put the hosts back in front 2-1 in first-half stoppage time, running past the Impact defense to win Michael Parkhurst's long ball. Goalkeeper Evan Bush overran the ball and Kamara touched it into the open net.
Federico Higuain made it 3-1 in the 48th minute by controlling a loose ball in the six-yard box and easing a ball into the back of the net. He scored his second goal five minutes later when he netted a penalty, though he and Kamara argued about who would take it.
Montreal quickly struck back as Didier Drogba pulled the Impact within 4-2 on a penalty in the 57th minute, and Piatti cut it to 4-3 a minute later when he finished Oduro's back pass.
Columbus clung to the lead until stoppage time when Drogba's glancing header of Ambroise Oyongo's long throw left Oduro open at the far post for an easy finish.
Montreal stayed in first place in the Eastern Conference, while ninth-place Crew SC missed a chance to move all the way up to fourth.
Clint Dempsey and Jordan Morris scored to help the Seattle Sounders beat the San Jose Earthquakes 2-0.
Dempsey scored his first goal from open play this season in the 26th minute when Erik Friberg cut the ball back for him to score from 15 yards.
San Jose had a chance to salvage a draw with five minutes after Tyrone Mears hauled down Víctor Bernardez in the box, but Chris Wondolowski's penalty hit post.
Morris put the game to bed in the 89th minute with a 20-yard strike from the top of the box -- his fourth goal in as many games.
The Earthquakes failed to score for the first time in 23 games.
Jermaine Jones scored in the 47th minute and the Colorado Rapids beat Real Salt Lake 1-0 in the Rocky Mountain Cup.
Kevin Doyle drew three defenders in the box and found Jones trailing the play. The U.S. international used the outside of his foot to squeeze a shot inside the far post.
Jones has three goals and two assists in four games with Colorado after being traded from the New England Revolution during the offseason.
The Rapids, who moved atop the Western Conference, have won the opening five home games of a season for the first time since 2003.
The Vancouver Whitecaps claimed a 2-1 win over the Portland Timbers after Christian Bolanos' shot slipped through the legs of goalkeeper Jake Gleeson.
Portland took the lead in the 34th minute when Darlington Nagbe put a shot past Vancouver goalkeeper David Ousted and Nat Borchers tapped it over the line.
Vancounver were back level when Masato Kudo beat Gleeson at his near post on the hour mark for his first MLS goal.
Gleeson made 11 saves but was at fault on the winner as Bolanos' soft chip slipped through his legs as he bent to pick it up in the 66th minute.
Rookie Tsubasa Endoh scored his first MLS goal in Toronto FC's 1-0 victory over FC Dallas in the Canadian team's long-awaited home opener.
Sebastian Giovinco set up the 28th-minute goal for Toronto in front of a sellout crowd of 30,025 at newly renovated BMO Field. Clint Irwin kept his fourth clean sheet of the season.
Giovinco has had a hand in all 10 Toronto goals this season, scoring six and assisting on the other four. Since joining Toronto for the 2015 campaign, the Italian star he has been directly involved in 48 of Toronto's 68 goals in league play.
FC Dallas finished the game with 10 men after goalkeeper Jesse Gonzalez was stretchered off with a neck injury in the 89th minute, forcing full-back Ryan Hollingshead to put on the keepers' gloves for the six minutes of added time as the visitors had used all their subs.
Dallas has lost three straight and not scored in 292 minutes.
Giles Barnes and Andrew Wenger scored in the first half and the Houston Dynamo beat Sporting Kansas City 2-0.
Barnes scored from distance in the 30th minute, rrunning past the defense to win Erick Torres' through ball and angling it past goalkeeper Tim Melia.
Wenger doubled Houston's lead in the first minute of first-half stoppage time when he powered a shot past Melia.
Houston, last in the Western Conference, snapped a three-game losing streak and a six-game winless stretch in its first victory since March 12. Sporting KC has not won in six games.
Former Houston captain Brad Davis started for Sporting KC in his first game against his former club after spending the past 10 seasons with Houston.