Philadelphia Union put one foot in the semi-finals of the CONCACAF Champions League on Tuesday, stunning Major League Soccer rivals Atlanta United with a 3-0 first leg away victory.

Two goals from Polish striker Kacper Przybylko left Union firmly on course for a place in the last four in what is the Pennsylvania club's first campaign in the regional club competition.

Przybylko, who had been influential in Philadelphia's last 16 victory over Costa Rica's Deportivo Saprissa, struck in the 57th and 73rd minute as Atlanta paid the price for poor finishing.

Atlanta dominated possession but fell behind early in the second half when Union defender Jakob Glesnes glanced a corner into the six-yard area, leaving the unmarked Przybylko to tap in.

Argentine midfielder Santiago Sosa almost levelled for Atlanta soon afterwards, but his dipping shot crashed off the cross bar on 60 minutes.

Instead, it was left to Przybylko to double his tally, collecting a pass from Leon Flach on the counter-attack before coolly tucking home the finish.

Philadelphia's third goal was almost a carbon copy of their second, only this time it was Przybylko playing creator, unselfishly squaring to Anthony Fontana to make it 3-0 four minutes from time.

The winners of the Philadelphia-Atlanta quarter-final will play either the Portland Timbers or Mexican giants America in the last four. Portland and America play their quarter-final first leg on Wednesday.

In the other half of the draw on Tuesday, Mexico's Cruz Azul outclassed Toronto FC 3-1 in their quarter-final first leg game at the Canadian club's temporary home at the Raymond James Stadium in Tampa.

The six-time CONCACAF champions had too much class for the MLS side, taking an early lead through Ecuadoran striker Bryan Angulo's superb curling long-range effort after just three minutes.

Jonathan Osorio gave Toronto hope with a 20th-minute equaliser but Cruz Azul regained the lead with Angulo's second on 34 minutes, tapping in from close range after the Canadians failed to deal with a setpiece.

Pablo Aguilar then extended the Mexicans' lead with another away goal in the second half, heading in from a free-kick on 58 minutes.

The winners of the Cruz Azul-Toronto tie face either MLS Cup champions Columbus Crew or Mexican side Monterrey in the last four.

Mexican clubs are looking to extend a long reign of dominance in the CONCACAF Champions League, having won the tournament for the past 15 years running. The last MLS side to lift the title were Los Angeles Galaxy in 2000.