La Liga leaders Barcelona were held to a 2-2 home draw by Celta Vigo on Saturday as their former assistant coach Juan Carlos Unzue dented the title hopes of the Catalans, who dropped points for the second game in a row for the first time this campaign.
Celta striker Iago Aspas silenced the Nou Camp by putting the visitors ahead in the 20th minute, knocking in on the rebound after splitting the home defence with a darting run through the middle.
Lionel Messi quickly replied at the other end, finishing off a sweeping team move two minutes later to score for the first time in six games in all competitions and net his 13th league goal of the season.
Suarez had a goal wrongly ruled out for offside before the break, the second time Barca have cursed their luck with referees in a week after Messi was denied a clear goal in the 1-1 draw at Valencia when his shot had clearly gone over the goal-line.
Messi helped set up what looked to be the winning goal for Luis Suarez in the 62nd minute as the striker thrashed home a Jordi Alba cutback but Barca were denied victory by another Uruguayan striker in Maxi Gomez.
He slotted in from close range after another searing run by Aspas, who capitalised on Barca defender Samuel Umtiti injuring his hamstring as he tried to keep up with the Spanish forward.
The France international is in danger of missing the "Clasico" against champions Real Madrid on Dec. 23 after Valverde said he believed the player had torn the muscle.
"The injury cost us the goal, it was an accumulation of catastrophes, because of the draw and the injury," the coach told a news conference.
"Losing Samuel right now is a big loss, he was in excellent form."
Gerard Pique missed a gilt-edged chance to hit the winner but struck the near post from close range while Messi, who also hit the woodwork earlier in the game, sent a free kick deep in stoppage time just wide of the post.
"We kept trying to win the game and had chances to do that. We have dropped two points but this is nothing that hasn't happened before," Valverde added.
Barca still lead the standings with 36 points but second-placed Valencia can cut their deficit on the leaders down to two if they beat Getafe on Sunday.
Later on Saturday Atletico Madrid, third on 27 points, host Real Sociedad while champions Real Madrid, also on 27, visit struggling Athletic Bilbao.
(For more sports news and updates, follow Ahram Online Sports on Twitter at @AO_Sports and on Facebook at AhramOnlineSports.)