TORONTO -- On an afternoon Sebastian Giovinco became the all-time Major League Soccer points leader, Toronto FC got its finishing from elsewhere on Saturday.

Jonathan Osorio, team captain Michael Bradley and Jozy Altidore scored to lift Toronto over the last-place Chicago Fire, who have yet to win on the road this season.

Giovinco, who is in the running for MLS MVP with 35 points, assisted on the goals from Osorio and Bradley, his first assist giving him the league record.

With four games left in the regular season and the Reds playing for favourable post-season positioning in what would be their first playoff appearance in franchise history, every game is huge.

The Reds are in fifth in the Eastern Conference, and would host a playoff game in Toronto if they can move past fourth-place D.C. United. The Montreal Impact, meanwhile, is hot on Toronto's heels in sixth.

On paper, the game in front of 22,513 sun-drenched fans at BMO Field, was Toronto's to lose. Chicago (7-18-6) has the worst record in the MLS.

But it wasn't until the 79th minute that Altidore scored the game-winner, after a scramble in front of the net off a Giovinco corner kick.

Osorio scored in the 29th minute on a goal that initially looked like Giovinco's. The tiny Italian corralled the rebound on his own corner kick, then chipped the ball into the box and off the driving Osorio.

Bradley scored in the 59th minute, winding his way through several Chicago players to score from inside the box.

Facing his former team for the first time, Gilberto clearly came to play. The Brazilian forward, who had seven goals and five assists for Toronto in 2014, took less than a minute to get back at his old team, capitalizing on a TFC turnover to slot the ball past Toronto 'keeper Chris Konopka.

Gilberto, who became expendable when Toronto signed Altidore, giving the club one more than the allowable three designated players, scored again in the 52nd, after some sloppy tackling in the midfield by Toronto FC.

The Fire was coming off an emotional week that saw their Canadian coach Frank Yallop, and assistants, including Canadian Marc Bircham, fired last Sunday.

Toronto hosts Philadelphia, New York and Columbus before capping their regular season in Montreal.