Chris Donovan scored the winning goal in the 11th minute of stoppage time to send the Philadelphia Union through to the Semi-Final of the Leagues Cup.
The Union took an early lead through Jesús Bueno, who scored his first goal for the team. However, Querétaro shocked Subaru Park when they equalised in the 65th minute through Ángel Sepúlveda.
The game was seemingly heading towards a penalty shootout before Donovan became the unlikely hero. Kai Wagner had gotten away down the left wing before playing a low ball across the penalty area. Donovan did well to get away from the Querétaro defenders before latching onto Wagner's pass. He remained composed and put the ball beyond Fernando Tapia.
Daniel Gazdag missed the quarter-final match due to the injury he suffered in the penalty shootout win over NYRB. Jesús Bueno, Olivier Mbaizo and Mikael Uhre returned to the starting XI, while Olwethu Makhanya was named among the substitutes.
The game kicked off over an hour after the original kick-off time due to a power outage at Subaru Park.
Jesús Bueno gave the Union the lead in the tenth minute with his first goal for the club. Jack McGlynn took the ball into space away from the Querétaro players before directing a ball towards the penalty area. It dragged in the direction of Bueno, who did well to get the ball under his control before prodding a volley into the bottom corner.
Julián Carranza hit the post in the 18th minute. Bueno headed Fernando Tapia's goal kick towards Uhre, who then flicked it on for Carranza. The Argentinian appeared to control the ball with his arm before striking the ball, and it hit the post before bouncing wide of the target. Had the chance resulted in a goal, it would not have counted as the visitors were soon awarded a free-kick for an infringement.
Following the Carranza opportunity, Querétaro dominated possession as they looked for a way beyond the Philadelphia defense. However, the Union were happy to keep the game in front of them, restricting the Liga MX side to corners, as Andre Blake was left untested.
Philadelphia had a great chance in the 39th minute. McGlynn's initial cross was cleared as far as Kai Wagner, who curled an excellent ball into the box. It was fizzed in with such pace that it only needed a header to guide it into the back of the net. Mbaizo was the player that went up for it, but he could not connect with the ball as it evaded everybody inside the penalty area.
HALF-TIME: Philadelphia Union 1-0 Querétaro
The start of the second half saw both sides battling to take control of possession, as neither side carved out an opportunity despite getting into attacking positions.
In the 62nd minute, the Union made a double change as Leon Flach and Chris Donovan replaced McGlynn and Uhre.
Ángel Sepúlveda levelled for Querétaro in the 65th minute. Jaime Gomez played a cross from the right deep into the penalty area towards the back post. Sepulveda managed to get the wrong side of Jakob Glesnes before hooking a volley across the goal and towards the far corner. The well-taken strike left Blake rooted to his spot as it bounced into the back of the net.
The Querétaro bench was in uproar in the 71st minute after Mbaizo body-checked Raúl Sandoval. The Querétaro man went down clutching his throat after the challenge causing the visiting bench to leap off their seats in protest. VAR checked the incident but saw no wrongdoing as the game continued.
Jim Curtin made two more changes in the 78th minute as Philadelphia changed their formation. Joaquín Torres replaced Damion Lowe, signalling a change to a back four. Nate Harriel replaced Mbaizo at right-back as the game entered its final stages. The Union were forced into their fifth and final change seconds later when Carranza went down clutching his leg. He was replaced by Quinn Sullivan.
Sullivan forced Tapia into a save in the 83rd minute. He received the ball from over 20 yards out and opted to try his luck. Sullivan's shot had plenty of power but was palmed behind the post for a corner, which came to nothing.
Omar Mendoza was sent off in the seventh minute of stoppage time. Torres had caused the visitors issues since coming on and went on a run towards the penalty area. Mendoza had to bring the tricky forward down by grabbing around his neck, forcing the referee to brandish a second yellow card, thus giving him his marching orders.
From the resulting free-kick, the Union hit the post. Wagner's free-kick deflected off the wall towards the six-yard box. It went in the direction of Jack Elliott, who needed just a touch to give the Union the lead. Unfortunately, he could not get a touch as it ended up hitting the post and bouncing away.
In the final moments of stoppage time, Donovan caused bedlam at Subaru Park. The ball was played down the left for Wagner, with the Querétaro defense stretched. He played it into the box with Donovan all alone, and he struck the ball beyond Tapia and into the back of the net. The forward did well staying in line with the ball and avoided being in an offside position following a VAR check.
FULL-TIME: Philadelphia Union 2-1 Querétaro
Philadelphia Union: Blake, Mbaizo (Harriel 78'), Glesnes, Elliott, Lowe (Torres 78'), Wagner, Bueno, Martinez, McGlynn (Flach 62'), Uhre (Donovan 62'), Carranza (Sullivan 81')
Unused Substitutes: Bendik, Trent, Real, Rafanello, Makhanya
Querétaro: Tapia, Mendoza, Escamilla, Manzanarez, Perlaza (Sandoval 63'), Barrera, Sierra (Gularte 70'), Lopez (Garcia 63'), Gomez (Montecinos 80'), Sanvezzo (Ayon 80'), Sepúlveda
Unused Substitutes: Yrizar, Zuniga, Garcia, Arana, Sakamoto, Varela, Gonzalez