Morelia's 3-3 tie with Leon in Estadio Morelos was stopped temporarily in the second half after anti-gay chants were repeatedly aimed at Leon goalkeeper Rodolfo Cota.
Referee Jose Alfredo Penaloza suspended the Liga MX 2019 Apertura quarterfinal first leg for five minutes close to the end of the match, following the procedure Liga MX laid out back in September.
The PA had asked fans to refrain from shouting the chant -- which has been used by fans in Mexico for some time -- after half-time with the game heating up and then halted the game momentarily, but players were removed from the field and made their way to the benches for a five-minute period when it continued.
Mexico's football federation (FMF) and Liga MX are attempting to crack down on the controversial goalkeeper chant that FIFA has ruled anti-gay, with the FMF fearful of not making Qatar 2022 if it occurs regularly during World Cup qualifying.
It isn't yet known whether Morelia's next home game will be played behind closed doors, which is the next step in the Liga MX and FMF's discrimination protocol.
Second-seed Leon took the lead when Jose Juan Macias was fouled inside the penalty area and converted the penalty, but seventh-seed Morelia responded two minutes later in the 10th minute through Peru international Edison Flores.
Ecuadorian Angel Mena struck from outside the penalty after to put Leon back in the lead in the 18th minute, with Morelia once again leveling through Flores.
Fernando Navarro finished a long passing move to once again hand Leon the advantage three minutes after half-time and the away side looked to be heading towards victory when Morelia's Gabriel Achilier saw red in the 51st minute.
But Leon also went down to 10 players when Yairo Moreno was sent off 10 minutes from full-time, and Luis Mendoza eventually equalized in the sixth minute of second half injury-time.
The second leg will take place at Estadio Leon on Saturday.
In Wednesday's other quarterfinal, fourth-placed side Queretaro fell 3-0 on the road to Necaxa.
All three goals came in the second half, with Cristian Calderon, Felipe Gallegos and Eduardo getting on the scoresheet.
That second leg is also Saturday. In Liga MX's other quarterfinal first legs, Santos Laguna face Monterrey and Club America hosts Tigres, with both games on Thursday.