The home side had the first real chance of the match when Henrique Sereno met Patrick Ebert's cross but couldn't beat Cristian Alvarez.
Espanyol's job was made much harder just before the interval when Victor Alvarez received a pair of bookings within minutes. First he was cautioned for a reckless challenge before being carded for a handball.
It was the struggling Catalan club who surprisingly took the lead, however, when Joan Verdu converted from 12 yards after Antonio Rukavine brought down Samuele Longo in the area.
Espanyol couldn't hold out though as Oscar Gonzalez headed an equaliser for the hosts with ten minutes remaining.
A point for Valladolid sees them rise to seventh, while Espanyol remain rock bottom, three points from safety.