Lionel Messi scored the 500th goal of his career against Valencia at the Camp Nou - but couldn't arrest Barcelona's worrying slide as they fell to yet another defeat.
After crashing out of the Champions League at the hands of Atletico Madrid in mid-week, Luis Enrique would have been looking for a reaction from his side as they looked to reassert their authority in La Liga.
However while it was a night of personal achievements for Messi, who managed his 500 goals in 631 games and also has 231 assists to his name, ultimately it was another poor night for Barca, who are in the midst of a mini crisis.
Things got off to a bad start for the home side when Ivan Rakitic put the ball into his own net with 26 minutes gone, and alarm bells started ringing when Santi Mina scored on the stroke of half-time.
Messi claimed his place in history just after the hour mark following some fine work from Jordi Alba, but try as they might, Barcelona were unable to pull themselves level.
The result means that Barcelona have won just one of their last six games - and that victory came in the first leg of their Champions League tie against Atletico which they went on to lose.
Earlier on in the day, Atletico Madrid comfortably beat Granada, while Real Madrid followed up their Champions League success against Wolfsburg with a 5-1 win over Getafe on Saturday.
That means that just one point separates the top three in La Liga with just five games remaining. Barcelona had previously held a ten point advantage over Real and a six-point lead over Atletico.