Lanus put five past Zulia as Chapecoense were held by Nacional in the Copa Libertadores on Tuesday.
Lautaro Acosta, Jose Sand, German Denis, Alejandro Silva and Nicolas Pasquini were on target in Lanus' 5-0 rout of visiting Zulia.
Acosta opened the scoring in the fifth minute, nipping in front of his opponent to poke the ball past Renny Vega at Estadio Ciudad de Lanus.
Lanus piled on the goals in the second half, scoring four from the 47th minute onwards as the Argentine outfit moved top of Group 7 following the 1-1 draw between Chapecoense and Nacional.
Grief-stricken Chapecoense were riding an eight-game winning streak in all competitions before kick-off, having won the second stage of Santa Catarina's state championship on Sunday.
Chapecoense claimed their first title since last November's tragic plane crash, which killed 71 people on board en route to Medellin for the first leg of the Copa Sudamericana final against Atletico Nacional.
Reinaldo - who scored against Joinville on the weekend - broke the deadlock from the penalty spot in the 10th minute, much to the delight of the home faithful.
But Chapecoense were pegged back four minutes before half-time when Hugo Silveira equalised for the Uruguayan visitors.
Meanwhile, Sporting Cristal and The Strongest played out a goalless stalemate in Group 2.