The hosts added to the lead with Jonathan "Jony" Rodriguez 20 minutes later, but Valladolid came back with a goal by Joaquin Fernandez before halftime and a penalty converted by Enes Unal in the second half.
It was the fifth straight match without a win for Alaves, which has likely fallen out of contention for the final Champions League spot. It is eighth in the standings with 46 points from 33 matches. Valladolid, which is just outside the relegation zone, also hasn't won in five straight matches. The team owned by former Brazil star forward Ronaldo was promoted to the first division this season for the first time since 2013-14.
Spanish league leader Barcelona hosts Real Sociedad on Saturday. Barcelona has a comfortable nine-point lead over second-place Atletico Madrid, which visits Eibar.
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