Jonathan Osorio scored in the 89th minute as MLS holders Toronto came from behind to draw first blood in their absorbing CONCACAF Champions League quarter-final tie against Tigres UANL.

Osorio produced a moment of brilliance thanks to a sensational backheel with a minute of regulation time remaining to lift Toronto to a thrilling 2-1 victory over the Mexican visitors on Wednesday.

Former Marseille forward and 36-time France international Andre-Pierre Gignac was named among the substitutes for Tigres at BMO Field but the match changed after his introduction.

Brought on for Enner Valencia at half-time in Toronto, Gignac proved a handful for the hosts as Chile star Eduardo Vargas broke the deadlock in the 52nd minute.

Vargas hit a half-volley across Toronto goalkeeper Alexander Bono but Tigres' lead was short-lived – Jozy Altidore outmuscling his opponent and finishing low beyond Nahuel Guzman eight minutes later.

And Toronto completed their comeback during the dying moments when Osorio backheeled in a Sebastian Giovinco pass to spark wild celebrations.

Seattle Sounders made it two wins from two games for American teams against Mexican opposition on Wednesday after edging Guadalajara 1-0.

The match was petering out for a draw until United States star Clint Dempsey broke the deadlock with 12 minutes left.

Sounders veteran Dempsey side-footed a shot past Rodolfo Cota at CenturyLink Field.