The Portugal striker nodded in a late equalizer after his goalkeeper misplayed a corner kick to concede Raul Garcia's opener.Valencia secured a dramatic 1-1 draw with Atletico Madrid thanks to a last-gasp Helder Postiga equalizer after Raul Garcia had given the visitors the lead thanks to a howler from Vicente Guaita.
Guaita punched a corner back across goal to allow Garcia to head home midway through the second half, as Diego Simeone's side looked set to edge a tight encounter and secure a first-leg advantage.
However, Postia popped up in stoppage time to turn home Sofiane Feghouli's cross and ensure his side takes a well-earned level score back to the Vicente Calderon for the second leg of the last-16 tie.
Both sides made a number of changes from last weekend's Liga action. Joao Pereira, Andres Guardado, Javi Fuego, Michel and Fede Cartabia came in for Valencia, while Vicente Guaita got the nod in goal. Atletico, meanwhile, gave a rare start to midfielder Joshua Guilavogui.
Valencia created the first chance after an even 20 minutes, with Miranda blocking Bernat's effort after Michel's cross, before the full-back then fired a shot wide. Raul Garcia was then thwarted by Guaita in Atletico's best opportunity, with the goalkeeper saving superbly after Adrian teed up the midfielder.
Valencia dominated possession but chances remained at a premium for the remainder of the half until the brink of the whistle, when Diego Costa raced clear on the counter thanks to Adrian's pass — only for Ricardo Costa to block his effort.
Thibaut Courtois was called into action shortly after the break, diving low to keep out Fede's effort from 20 yards. Chances remained few and far between, with Valencia unable to find a breakthrough while Atletico waited for the opportunity to counter, but the deadlock was finally broken after 72 minutes.
Guaita made a bizarre mess of an attempted punch from a corner, succeeding only in diverting the ball back across goal to Garcia, who headed into the top corner from point-blank range.
Diego Costa then went into the referee's notebook for diving after going down under a challenge from Ricardo Costa in the penalty area before any contact was made.
Valencia spurned a golden opportunity to draw level when Courtois parried Pablo Piatti's effort out to Canales, but the midfielder failed to get over the ball and turned the rebound over the bar. Courtois then pulled off another stunning stop to deny Feghouli, who bustled his way past three challenges, only to see his fierce effort beaten out.
Atletico remained resolute and looked to have ensured the win until injury time, when Postiga burst onto Feghouli's cutback to head the ball into the unguarded net and set up a mouthwatering second leg in the capital.