Brighton have lost 3-2 against Atletico Madrid in front of 31,000 at the Amex Stadium.
Chris Hughton's side came from behind twice through goals from Pascal Gross and Steve Sidwell.
However, it wasn't enough as Lucas Hernandez scored the winner for the La Liga outfit.
Nicolas Gaitan and Fernando Torres also scored for Diego Simeone's side.
The Premier League new boys start the season at home against Manchester City next weekend.
Source: tribalfootball.com