America took the lead against Atlante but could only draw 1-1, a result which left its Mexican Clausura championship playoff hopes up in the air.
In other 16th round matches Sunday: Estudiantes came back from a four goal deficit to tie 4-4 against Toluca, and Tigres outplayed Morelia 3-0 to remain second in the overall standings.
Angel Reyna put America ahead from Pavel Pardo cross in the 35th but Venezuelan striker Giancarlo Maldonado scored the equalizer in the 38th.
Reyna has 12 goals and leads all scorers.
Atlante has 24 points to lead Group 2, followed by Atlas and America with 23 each, while Toluca is still alive with 21.
America will have a tough time to qualify for the finals as they travel to Brazil to play Santos on Wednesday and will play Pumas in their last match of the season next Sunday.
In Morelia, Lucas Lobos scored in the 14th, before Alan Pulido (84) and Alberto Acosta (87) added late goals for Tigres who now has 32 points, just three less than the tournament leader Pumas.
In Toluca, the Red Devils took a 4-0 lead in the first half as Nestor Calderon (10), Antonio Naelson (17th) and Emanuel Cerda (32nd and 39th) scored.
However, Edgar Duenas scored an own goal (47th) and Eduardo Lillingston notched two strikes (54th and 80th), before Juan Carlos Leano capped an incredible comeback for Estudiantes with an equalizer in the 84th.
