Alaves claimed top spot in LaLiga following Tomas Pina’s second-half winner in the 1-0 success at Celta Vigo.
Midfielder Pina smashed home from close range in the 58th minute at Balaidos after the ball was laid back to him by Victor Laguardia.
The visitors, who are now a point clear of second-placed Sevilla having played a game more, went into the match on the back of a morale-boosting victory over European champions Real Madrid before the international break.
They could have fallen behind in the 35th minute when Celta’s Southampton loanee Sofiane Boufal was narrowly off target from the edge of the box.
Spain forward Iago Aspas went even closer for the hosts nine minutes into the second period when he rattled the right post with a powerful free-kick.
Pina then pounced to break the deadlock, before Alaves goalkeeper Fernando Pacheco produced fine saves to prevent Boufal and Brais Mendez from equalising as Celta’s winless run stretched to six matches.