Arda Turan turned home from close range after 30 minutes to put Atletico 2-0 ahead, but Viera made up for his penalty miss with a strike in the latter stages of the first period.
The scoring were not finished in the first half, however, as Turan notched his second after 44 minutes to leave the visitors 3-1 ahead at the interval.
Read how it all unfolded in Sports Mole's minute-by-minute live commentary of the action below.
RAYO: Ruben; Tito, Baena, Arbilla, Nacho; Saul, Trashorras; Bueno, Lass, Viera; Larrivey
ATLETICO: Courtois; Manquillo, Miranda, Godin, Filipe; Sosa, Koke, Gabi, Turan; Costa, Villa