Barcelona - Lionel Messi scored in a ninth consecutive match but his latest double on Saturday was only enough to earn Barcelona a 2-2 draw against Valencia.
Messi instigated another Barca comeback at the Camp Nou before placing an injury doubt over his availability for Wednesday's Copa del Rey Clasico against Real Madrid.
Ernesto Valverde confirmed after the game his captain had felt a "small problem" but insisted it was nothing serious.
Valverde is still unlikely to take any risks given Barcelona's testing month ahead, even if Messi's absence, however brief, would be a blow, particularly while he is in such irresistible form.
Kevin Gameiro and Dani Parejo's penalty gave Valencia a surprise two-goal lead but Messi pulled one back with his own spot-kick before curling in a brilliant equaliser with 26 minutes left.
After their stunning turn-around against Sevilla in midweek, Barca looked destined again to finish the job, but at the end of a breathless contest, Valencia had held on for a point.
"When you don't win, you always feel you have missed something," Valverde said. "But the league is long and there are matches where you come up against a good team. This was one of those."
Messi's 20th and 21st league goals of the season leave his team six points clear of Atletico Madrid, who could cut the gap to three by beating Real Betis on Sunday, with Real Madrid, 11 points back, at home to Alaves.
After eight consecutive Barcelona wins in La Liga, this result perhaps offered the chasing pack a little encouragement at least.
Real could inflict further disruption themselves. The first leg of the Copa del Rey semi-finals on Wednesday will be the first of three Clasicos in a month. The latter two will be back-to-back, within four days.
But Messi fit and in this sort of form means any confidence Real feel comes with an asterisk.
His 12 goals in his last nine games is the same number the whole Valencia squad managed in their first 15 league matches. Valencia were 15th in December, with only three wins, and their coach Marcelino was under pressure, just six months after propelling them back into the Champions League.
The club kept faith and results have improved. They have now lost only one of their last seven matches and are within sight of the top four.
Valencia deserved their first-half lead and could have scored sooner, Parejo drawing a smart save from Marc-Andre ter Stegen before Denis Cheryshev lashed the rebound off the far post.
The visitors rode their luck as two decisions went their way in a matter of minutes. First, Barca could have had a penalty when Gabriel Paulista blocked Nelson Semedo's shot with his hand.
Then the home team should have had a free-kick as Messi was bundled over by Parejo. The latter proved key, with Valencia sprawling forward on the counter-attack.
Rodrigo carried the ball 40 yards before slipping a cute reverse pass behind Vermaelen and Gameiro banged in the finish.
Valencia's penalty was clear after Sergi shoved Daniel Wass in the back, with Parejo whipping the ball into the corner to make it two.
Barca looked shell-shocked but the third goal in 15 minutes was theirs. Semedo beat Toni Lato to Arturo Vidal's pass and tumbled after a clip on his shin. Messi slammed the loose ball into the top corner but the whistle had blown. He rolled in the penalty instead.
Sergi's shot crashed against the post and Barca were dominant after half-time. At the other end, on a rare Valencia break, Rodrigo should have made it three but, on the stretch, put it over from six yards.
That was in the 63rd minute, and in the 64th, Barcelona were level. Vidal teed up Messi, who teed up his own left foot and curled the ball inside the post.
The teams, and the crowd, seemed to take a breath, in anticipation of a late push, but it never came. The draw was a fair result.