Jean Meneses opened the scoring and Angel Mena scored a late goal that could be valuable next week, as León defeated Los Angeles FC 2-0 in the first leg of the Concacaf Champions League round of 16.
Chilean Meneses made a great individual play and scored the first goal in the 21st minute, and Mena extended the lead in the 88th minute for the Mexican team, which is participating for the second time in its history in the regional club tournament under its current format.
Before, León played in the tournament in the 2014-15 season when they were eliminated in the group stage.
To stay alive, León can afford to lose by 1-0 against the MLS team in the second leg, which will be played next Thursday at the Banc of California Stadium in Los Angeles.
LAFC, making its tournament debut, needs to win by 2-0 to send the series to penalties.
The winner of this series will face the winner of the Cruz Azul and Portmore United from Jamaica match.
The match was the first one played with a club in his country by striker Carlos Vela, who was the Most Valuable Player of the MLS last season, scoring 34 goals, a record.
Vela was part of Chivas' youth academy, but never made his debut in Mexico and after becoming champion in the U17 World Cup in Peru 2005, he moved to Arsenal in England.
León took the lead when Meneses took control of a ball on the left side, eluded a defender and entered the area to take a low shot that went in next to the right post of Dutch goalkeeper Kenneth Vermeer's goal.
The away team threatened towards the end of the first half, but their best chance came in the 54th minute, when Francisco Ginella received a pass inside the area and took a curling shot that went past goalkeeper Rodolfo Cota and hit the left post.
In the final stretch, Mena received a pass from Luis Montes and connected with a right-footed shot that went in next to Vermeer's left post, giving the Mexican club a wider margin for the second leg.
Also on Tuesday, Argentine Lucas Passerini and Uruguayan Jonathan Rodríguez scored a pair of goals in stoppage time to give Cruz Azul a 2-1 victory over Portmore United from Jamaica.
Rondee Smith put the hosts ahead in the 73rd minute, but Passerini equalized in the 95th minute and Rodríguez scored the winning goal for the Mexican team in the 98th minute.
The second leg will be next Tuesday at the Estadio Azteca in the capital.
In another Champions League match, Motagua from Honduras drew 1-1 with Atlanta United from the MLS. (D)