Toronto's title defence failed to ignite after the winless MLS champion crashed to consecutive defeats, while Atlanta United routed a 10-man Vancouver Whitecaps side.
Saturday saw Sebastian Giovinco's Toronto upstaged by Canadian rivals Montreal Impact 1-0 at Stade Olympique.
Toronto has been flying high in the CONCACAF Champions League , where the club is set to meet Mexican giant America in the semifinals, but the MLS titleholder has struggled domestically.
Greg Vanney's side is still searching for its first win of the MLS season after Jeisson Vargas' deflected shot four minutes before halftime lifted the Impact to victory number one in 2018.
TFC is rooted to the bottom of the Eastern Conference standings, along with the Chicago Fire, which lost 2-1 at Minnesota United.
Playing in front of 45,000 fans in Atlanta, the hosts crushed Vancouver thanks to Kendall Watson's 13th-minute red card and Josef Martinez's hat-trick.
Watson was dismissed for a foul on Leandro Gonzalez Pirez following a video review and Martinez converted the subsequent penalty.
It was one-way traffic from that point as Aaron Maund scored an own goal in the 58th minute before Martinez added a third on the hour-mark.
Substitute Erik Hurtado managed to pull a goal back for the visitors but Martinez completed his hat trick with two minutes remaining after heading past Stefan Marinovic.
Atlanta is third in the east and three points behind unbeaten New York City, which made it three wins from as many matches thanks to their 2-0 victory over Orlando City.
After a scoreless first half, Ismael Tajouri scored his first MLS goal thanks to some shocking play in the back from Orlando.
Maximiliano Moralez added a second for NYCFC as part of a brilliant team move, continuing a rough start to the 2018 season for Orlando.
Luciano Acosta was the hero for D.C. United, with his 97th-minute equalizer salvaging a dramatic 2-2 draw at home against the Houston Dynamo. The match was notable for taking place at Maryland SoccerPlex, the smallest venue to ever host an MLS game.
Sporting Kansas City overcame the San Jose Earthquakes 3-2 in a thriller that saw Chris Wondolowski net his 135th MLS goal, the Philadelphia Union and Columbus Crew played out a goalless draw and Real Salt Lake edged the New York Red Bulls 1-0.