Tigres appeared on course for their seventh win of the campaign when Lucas Lobos put them ahead in the 27th minute, but substitute Carlos Ochoa netted in the dying seconds to claim a point for the visitors.
That allowed second-placed Atlas to narrow the gap with a 1-0 win over Tijuana, thanks to Omar Bravo's strike in the third minute.
The visitors had Joshua Abrego sent off seven minutes from time.
Christian Benitez netted a hat-trick as third-placed Club America dispatched Cruz Azul 3-0 in a game which saw both teams finish with 10 men.
The hosts were 2-0 up by the break thanks to strikes from Benitez in the 23rd and 41st minutes, in between which Israel Castro was sent off for Cruz.
The numbers were evened up just after the hour when Paul Aguilar also saw red, but Benitez grabbed his third in the 69th minute to complete a comfortable victory.
Goals from Christian Suarez (42) and Angel Reyna (70) gave Pachuca a 2-1 win over San Luis, who briefly levelled the scores through Marco Perez (56).
Elsewhere, Queretaro saw of Monterrey 1-0 thanks to Wilberto Cosme's third-minute strike, while Diego De Buen (52) was on the scoresheet as Puebla won at Leon by the same scoreline.
Puebla had Jaime Duran sent off late on.