Castro scored the only goal of the game as Real Mallorca claimed all three points from their home fixture against Real Betis this evening.
The midfielder won the match for the islanders with just 24 minutes on the clock, scoring from close range following a passing move.
However, the game will be more remembered for the three red cards that were brandished after the break.
Ivan Ramis and Víctor Casadesus were sent off for Mallorca, while Alvarez saw red for the visitors.