TORONTO — Jonathan Osorio scored on a delightful backheel in the 89th minute to give Toronto FC a 2-1 win over Tigres UANL in an enthralling clash of champions Wednesday in the opening leg of the Scotiabank CONCACAF Champions League quarterfinal.

The goal came after some extended Toronto pressure with Sebastian Giovinco finding Osorio in front of goal. The ball was slightly behind him so Osorio pivoted like a ballet dancer and backheeled it home.

A key stoppage-time tackle by Chris Mavinga preserved the tie.

Toronto won the MLS Cup last season while Tigres finished as Liga MX champion. And for the 25,587 at BMO Field, the star-studded contest did not disappoint — building from a slow burn in the first half to all action in the second with Toronto pulling ahead in the final minutes.

The second leg of the aggregate series is March 13 at the 42,000-capacity Estadio Universitario. Toronto will head south full of confidence, full value for the win. Tigres, meanwhile, will hope its away goal will play its part in the rematch.

Toronto had looked good to open the second half but Chilean international Eduardo Vargas turned the tide, outmuscling Mavinga before slamming a difficult right-footed shot past Alex Bono in the 52nd minute.

Osorio had a glorious chance to tie it up just minutes later, but he skied his shot from point-blank range from a low Jozy Altidore cross.

Altidore evened the score in the 60th, holding off Tigres Brazilian-born captain Juninho to fire a low shot home. Giovinco started the play by finding Marky Delgado, whose quick relay carved open the Mexican defence.

Altidore could have made it 2-1 in the 70th minute but the burly American could not control a wonderful pass from captain Michael Bradley that found him in front of goal. Defender Drew Moor then came close with a header off a Bradley free kick.

And Tigres seemed to escape a late handball in its penalty box.

Commissioner Don Garber has called the CONCACAF club championship a "referendum" for MLS in its bid to become the dominant circuit in North America.

Mexican teams have won the last nine editions of the tournament since it changed to a Champions League format in 2008-09. Mexican squads were runners-up in seven of those finals with Real Salt Lake (2010-11) and the Montreal Impact (2014-15) also making the final.

In quarterfinal action Tuesday, the New York Red Bulls won 2-0 at Club Tijuana — just the third victory in 49 competitive matches (3-38-8) on Mexican soil for MLS teams. The other two wins — FC Dallas over Pumas and Seattle over Monterrey, both by 1-0 margins — came in 2011 Champions League group play.

MLS teams were 0-26-5 in CONCACAF League/Cup knockout games in Mexico before the Red Bulls' win.

Spanish playmaker Victor Vazquez, forced to leave TFC's season-opening loss to Columbus on the weekend with a nerve issue in his back, came on in the 79th minute. Vazquez played for Mexico's Cruz Azul prior to coming to MLS.

Tigres, managed by Brazilian-born Ricardo (Tuca) Ferretti, currently stands fourth in the Mexican league with a 5-2-3 record.

How deep are the Mexican champions? They could bring star French forward Andre-Pierre Gignac off the bench to start the second half. The former Toulouse and Marseille player, part of France's Euro 2016 runner-up squad, has seven goals so far this season in Mexican league play.

The Tigres starting lineup featured five Mexican internationals as well as Argentine international goalkeeper Nahuel Guzman, Ecuador international forward Enner Valencia (formerly of West Ham and Everton) and Chile's Vargas.

It was two degrees Celsius at kickoff but fans were bundled up at BMO Field. Toronto manager Greg Vanney skipped a coat, however, wearing a suit bolstered by a quilted waistcoat.

Both teams came out in 3-5-2 formations, dropping to a five-man backline when the other team had the ball.

Tigres came as advertised, full of skill and pinging accurate passes around the field despite the uneven early March grass surface. Toronto looked to counter-attack, gradually building into the game as the half wore on with Giovinco pulling the strings.

Argentine Lucas Zelarayan forced the first save by Bono in the 20th minute, on a free kick from just outside the box. But Toronto had a better chance in the 31st minute with Guzman using his right leg to stop a Giovinco shot off an Altidore feed.

They were the only two shots on target in the first half, which saw Tigres have 58.7 per cent of possession.

TFC outshot Tigres 12-3 in the second half (4-1 in shots on target), and 13-5 throughout the match (5-2 on target).

Altidore screamed for a penalty in the 49th minute when he was bodied to the ground in the Tigres penalty box but Costa Rican referee Ricardo Montero was unmoved.

As the game wore on, Tigres defenders treated the diminutive Giovinco like a pinata.

The Toronto-Tigres series winner will face either Mexico's Club America or Panama's Tauro FC in the semifinal. The tournament champion qualifies for the annual FIFA Club World Cup.

Toronto dispatched Colorado 2-0 on aggregate in an all-MLS round-of-16 matchup. Tigres advanced by beating Costa Rica's C.S. Herediano 5-3 on aggregate.

Based in the Monterrey area, Tigres UANL (the full name is Club de Futbol Tigres de la Universidad Autonoma de Nuevo Leon) was runner-up in the tournament in 2015-16 and '16-17.

Founded in 1960, Tigres has been involved in four of the past five Liga MX finals (winning three).

Going into the game, Toronto's record against Mexican teams in the competition was 1-4-3. The lone victory was a 2-1 decision over visiting Cruz Azul in August 2010.

Toronto's best Champions League showing was in 2010-11 when it reached the semifinals, where it was beaten 7-3 on aggregate by Mexico's Santos Laguna.

Tigres winger Jurgen Damm lived briefly in Toronto, moving to Canada at the age of two due to his father's job. He tweeted his 1996-97 class photo from St. John School as well as pictures of a young Damm wielding a shovel in snow.

"After 21 years it is good to be back in Toronto. Good memories living with my family," wrote Damm, who started on the bench.