It was the away side that opened the scoring, however, when Piti found the back of the net with a cool finish after 14 minutes.
Celta pushed for the leveller in the latter stages, but they were stung on the counter when Andrija Delibasic made it 2-0 from close range.
Read how it all unfolded in Sports Mole's minute-by-minute live commentary of the action below.
CELTA: Varas; Cabral, Demidov, Lago, Johny; Pranjic, Oubina, Fernandez, Lopez; Park, Orellana
RAYO: Ruben; Casado, Figueras, Tito, Galvez; Fuego, Trashorras, Dominguez; Piti, Bangoura, Leo