Hirving Lozano struck in added time as Pachuca sealed their place in the final to beat Leon 3-2 on aggregate and set up a clash with Monterrey for the Liga MX title.
After a 1-1 draw at the Estadio Nou Camp, Pachuca were on course for victory after Leon defender Diego Novaretti fired into his own net to give Los Tuzos the advantage.
Leon, however, settled quicker into the second half, and Elias Hernandez tied the aggregate scoreline with a fierce shot from distance, contender for one of the goals of the season.
Pachuca then found it harder to gain a foothold, and a Leon onslaught followed.