Valencia started the match strongly, creating several scoring opportunities in the early stages. Luis Rioja, who made his first return to the Mendizorroza since leaving the club, came close to scoring with a well-executed strike that forced Antonio Sivera into an expert save.
The visitors continued to press for a goal, with Pepelu's strike being cleared off the line just five minutes after Rioja's chance. However, Alaves denied Valencia the lead in the 16th minute when Giorgi Mamardashvili made a stunning one-handed save to keep out Jon Guridi's close-range header.
The Georgian goalkeeper was in action again soon after, as he managed to get both hands on Nahuel Tenaglia's long-range strike after initially spilling the defender's effort. Alaves eventually took the lead in the 79th minute, with super-sub Joan Jordan scoring from the penalty spot after referee Jesus Gil Manzano awarded the hosts a penalty.
The win gives Alaves a four-point safety net above the relegation zone with only two matches left this season. Valencia, on the other hand, still holds a slim chance of finishing in the top eight despite the unexpected result.