The home side had the lead after 27 minutes when Antonio Amaya headed home from close range, with that goal separating the two sides at the interval.
Rayo were level in the early stages of the second half when Alberto Bueno finished from inside the box.
Betis regained the lead after 82 minutes when Verdu converted from the edge of the box, but Bueno's second in stoppage time secured Rayo a share of the spoils.
Read how it all unfolded in Sports Mole's minute-by-minute live commentary of the action below.
REAL BETIS: Sara; Nacho, Amaya, Figueras, Juanfran; Sevilla, Reyes, Nono; Vadillo, Castro, Molina
RAYO VALLECANO: Cobeno; Tito, Galeano, Martinez, Baena; Trashorras, Saul; Larrivey, Falque, Viera; Lass