Four days after Josep Maria Bartomeu resigned his presidency following months of criticism of Barcelona's ailing finances and struggles on the pitch, Antoine Griezmann cancelled out Luis Rioja's opener on another disappointing night for Ronald Koeman's side in LaLiga.
Current boss Koeman's mood after having his future plunged into a cloud of speculation will not have been improved by Alaves' opener.
Goalkeeper Neto failed to control a needless back pass after 31 minutes and Rioja dispossessed him before rolling the ball into the empty net.
Alaves' rearguard action suffered a blow after 62 minutes when former Brentford and Birmingham midfielder Jota picked up a second yellow card.
And the visitors levelled a minute later when Griezmann lifted the ball over Pacheco.
Pacheco denied Messi and Fati either side of Griezmann having an effort disallowed.
Barca were again denied a winner late on when Messi's strike was chalked off for offside and Gerard Pique fired wide in stoppage time.