03/03/2015 10:12 EST | Updated 05/03/2015 05:59 EDT

Porter's extra-time goal lifts Impact over Pachuca in CONCACAF quarter-final

MONTREAL - Cameron Porter was the unlikeliest of heroes for the Montreal Impact.

The 21-year-old who was picked in the third round of the Major League Soccer SuperDraft scored in extra time to lift the Impact to a 1-1 second-leg draw with Pachuca on Tuesday night. It gave Montreal the victory in their CONCACAF Champions League quarter-final on the away goals rule.

The Olympic Stadium crowd of 38,104 went wild and players mobbed Porter on the field after pulling off the win in the dying seconds— only 10 minutes after the Mexican side looked to have won the series on German Cano's goal from the penalty spot.

"Sheer ecstasy," was how beaming Porter described the feeling. "I didn't even know how to celebrate so I just started running, basically. And everyone piles on top of you and you find it hard to breathe."

The Princeton University product was the surprise of training camp when he impressed coach Frank Klopas enough to be given a contract. Now he has jumped ahead of third overall draft pick Romario Williams.

Cameron was sent in as a substitute for midfielder Nigel Reo-Coker in the 85th minute as Montreal pressed for the equalizer.

Another substitute, Calum Mallace, made the goal happen as he won a ball near the halfway line and lobbed a pass over the middle. Porter did well to stay onside, then took it off his chest, shook off a defender and slotted it past Oscar Perez.

"The reason we signed (Porter) is because he's so hard working and he takes risks like that," said Mallace, who went on in the 65th. "I saw him run off the shoulder of their right back and, sure enough, I hit the right ball. A great finish by Cam."

The teams tied the series 3-3, but Montreal won on the away goals rule after drawing 2-2 at Pachuca in the first leg last week.

The Impact will now face the winner of a quarter-final on Wednesday between D.C. United and Alajuelense, who won their first leg 5-2.

The crowd booed in the 80th minute as Pachuca was awarded the penalty after Pachuca's Jurgen Dam went down after some jostling in the area with defender Laurent Ciman.

Cano slotted it home to give Pachuca the short-lived lead in the match and the series.

The Mexicans did not look put off at all at playing in a dome and had the better of the play in the first half before Montreal mounted some dangerous attacks in the second. Pachuca had what looked to be a sure goal by Cano taken away by a sliding save by goalie Evan Bush in the 71st.

"The missed chances hurt us," Pachuca coach Diego Alonso said through an interpreter. "Our lack of experience also showed. We didn't manage the game well. But it was a learning experience that will help us in the rest of our season."

The Impact's hopes, and ticket sales, surged after the opening leg and they went with the same starting 11 for the return leg.

They were in their second Champions League quarter-final. They beat Santos Laguna 2-0 before 55,571 at the Big O in 2009 only to lose 5-2 in the second leg in Mexico. Now they have gone at least one step further.

"I'm happy for the team," said Klopas, who was shown the red card after the Porter goal and will sit out the first game of the semifinals. "It's a great moment now but we can't get too high."

The first leg of the semifinals will be played on a date between March 17 and March 19, with the second leg between April 7 and April 9.

Barring an MLS work stoppage, the Impact open league play Saturday against DC United.