Welterweight prospect Saul Alvarez remained undefeated Saturday, stopping Luciano Cuello in the sixth round of their scheduled 12-round fight in Guadalajara, Mexico.

Alvarez (33-0-1, 25 knockouts) put Cuello (26-2, 12 KOs) down in the first and second rounds.

The 19-year-old Mexican, known for his red hair, is scheduled to fight on the Sept. 18 card at Staples Center in Los Angeles. His opponent has yet to be determined.