Eibar threw away a one-goal lead in Friday's defeat to Rayo Vallecano as its winless La Liga run was extended to 11 matches.
Rayo Vallecano came from a goal down to beat Eibar 2-1 at the Estadio Municipal de Ipurua as the host's miserable run of form in La Liga continued.
Last season's Segunda Division winner were on course for a first victory since January after Mikel Arruabarrena's 35th-minute penalty, but trailed by the break as it failed to put distance between itself and its relegation rivals.
Arruabarrena opened the scoring from the spot 10 minutes before the interval to register his side's first goal in almost a month after Federico Piovaccari was felled by Cristian Alvarez.
However, the opener was followed by a swift collapse as Alberto Bueno registered his eight goal in five games to level soon after. The turnaround was complete when Manucho glanced home a corner three minutes prior to the interval.
A scoreless second half ensured Rayo moves into the top half with a third straight league win, while Eibar looks nervously over its shoulder at the drop zone just three points below.