Granada striker Isaac Success struck in the last minute to deny Valencia a much-needed win at Los Carmenes.
The visitors looked to be heading for a first victory in four games when Alvaro Negredo opened his account for the club with a stunning finish in the 84th minute.
But the game took an unexpected turn when substitute Paco Alcacer was shown a straight red card, and Granada made the extra man count, Success getting the final touch to a late goalmouth scramble to secure a 1-1 draw.
The draw saw Nuno Espirito Santo's side slip four points behind fourth-placed Sevilla, while Granada moved two points away from the relegation zone.
Granada made the brighter start and did most of the early attacking but the first clear chance fell to Valencia. Negredo knocked the ball through the legs of Jeison Murillo to advance towards goal but dragged his shot wide.
Early in the second period Manuel Iturra gobbled up a misplaced pass in the Valencia half but failed to take advantage of the opportunity, hitting a tame shot straight at Diego Alves.
A minute later Granada had the visitors on the ropes again but Dimitri Foulquier could not aim his volley on target
With 19 minutes remaining, Negredo came within inches of his first goal for Valencia, running onto a through ball from on the left hand side of the area but striking the outside of the post.
A couple of minutes later at the other end Granada striker Youssef El Arabi had the ball in the net but the goal was wrongly called offside.
The game looked to be heading for a goalless draw when Negredo produced a moment of brilliance to break the deadlock - chipping the ball into the air just inside the box to volley high into the net.
But there was still plenty of drama to come. Just four minutes after coming on to replace Rodrigo, Alcacer challenged Juan Carlos to try and win a high ball, with the Granada man slapping the striker on the face.
Alcacer responded by grabbing his opponent's shorts, prompting an overreaction from Juan Carlos, and the referee stunned the Valencia players by pulling out a red card for the Spain international.
Granada were left with four minutes to seize their numerical advantage and grabbed an equaliser in the final minute of normal time.
Foulquier met Piti's cross and Alves came out to claim the ball but could only punch it off another Granada player and into the path of Success, who stabbed the ball into the empty net.
ends