Thursday night's match at Pumas' Estadio Olimpico Universitario was action-packed at both ends of the field and could have easily ended with one or more additional goals having been scored, reports Efe news.
The visitors then opened the scoring in the 21st minute on a left-footed shot by 18-year-old Diego Lainez, who had set up the goal by shaking off the mark of midfielder Victor Malcorra and making an impressive run down the right side.
Paraguayan forward Carlos Gonzalez nearly scored twice in rapid succession, the first opportunity coming on a bouncing volley in the 24th minute that forced America goalkeeper Agustin Marchesin to make a foot save and the second on a header three minutes later that barely missed the mark.
Even so, the visitors squandered a golden opportunity to take a 2-0 lead in the 41st minute.
Lainez set up the chance by maneuvering around a defender on the left side of the area and delivering a pass to an unmarked Paul Aguilar, who had one shot stopped by Malcorra and another saved by Pumas goalie Alfredo Saldivar.
Aguilar's second attempt had been served to him on a platter after the ball had ricocheted off Malcorra's foot, yet the defender fired his close-range blast directly at Saldivar's chest.
After dodging that bullet, Pumas came back at the start of the second half and tied the score on a shot by Chilean midfielder Martin Rodriguez off a pass from defender Alan Mozo in the 51st minute.
The hosts then had a an excellent chance to take the lead in the 66th minute, but Gonzalez failed to pull the trigger in time after Marchesin had been pulled out of position.
America, for their part, had victory in sight in the 75th minute when they won a penalty on a hand ball by Luis Quintana, but Saldivar stopped Martinez's attempt from the 12-yard mark.
The two teams will meet again on Sunday evening at America's Estadio Azteca in the second and final leg of their semi-final of the Apertura 2018, the first of two competitions in the Liga MX's 2018-2019 season.
Meanwhile, fifth-seeded Monterrey notched a 1-0 home win over top-seeded Mexico City club Cruz Azul in Wednesday night's first leg of the other semi-final.
(This story has not been edited by Devdiscourse staff and is auto-generated from a syndicated feed.)