Fans fought a running battle with riot police on the terraces in the final 10 minutes of Saturday's match at the Tecnologico in the northern city of Monterrey noted for its drugs-related violence.
Fans who tried to jump on to the pitch were caught by police, handcuffed and left lying at the foot of the terraces until order was restored, according to pictures posted on the Record sports website (www.record.com.mx).
Monterrey were a man short for more than an hour after their former Olympique Lyon and Argentina striker Cesar Delgado was sent off in the 27th minute.
Leon, who had taken only one point from their previous four matches, went ahead just before halftime through Elias Fernandez and their Argentine striker Mauro Boselli secured the win 20 minutes from time.
Mexico forward Marco Fabian scored with a superb lob from outside the box three minutes into added time to give Cruz Azul a 1-0 win at home to Puebla that keeps the Blue Machine three points clear at the top of the Clausura championship standings.
"It was a stroke of genius…having the vision to see the goalkeeper off his line," Cruz Azul coach Luis Fernando Tena told reporters.
"Puebla had a great match, I don't think they deserved to lose, it should have been a draw… then we got a huge goal. The quality of our play is what tips the balance in such tight matches," he added.
Unbeaten Cruz Azul have strung together six consecutive wins in their seven matches for 19 points, scoring 14 goals and conceding two.
They are three points ahead of Toluca, who won 3-0 at Veracruz, and seven in front of America, the most consistent team last year who lost 1-0 at Morelia on Friday, their second consecutive defeat.
(Additional reporting by Carlos Calvo; Writing by Rex Gowar in London; Editing by Michael Hann)
