Real Madrid missed the chance to make La Liga history as they were held to a 1-1 draw by Villarreal at the Bernabeu.
Sunday's victory over Espanyol made it 16 league wins in a row for Los Blancos stretching back to March, equalling the all-time mark set by Pep Guardiola's Barcelona in the 2010-11 season.
But Zinedine Zidane's men were unable to secure the record outright as they fell behind to a Bruno Soriano penalty given for a Sergio Ramos handball on the stroke of half-time.
Ramos levelled three minutes into the second period with a towering header and Real dominated after a hesitant first 45 minutes, but could not find a second goal.
Madrid had plenty of possession but no chances to speak of until Villarreal goalkeeper Sergio Asenjo was called upon in the 18th minute to push clear Karim Benzema's close-range header after Gareth Bale had headed Marcelo's left-wing cross back across goal.
Real Madrid old boy Denis Cheryshev's powerful strike from the edge of the area had to be tipped over by Kiko Casilla. From the resulting corner Nicola Sansone, who scored from 60 yards against Real Sociedad at the weekend, attempted another goal-of-the-season contender but sent a spectacular scissors-kick volley wide.
Cristiano Ronaldo's first chance arrived on the half-hour mark, but his downward header from James Rodriguez's cross from the left was comfortably held by Asenjo.
Bale was well off target with a left-footed strike from 25 yards as the half entered its final 10 minutes, with Benzema's header still the only true opening they had created.
Marcelo came off with two minutes of the half remaining with what appeared to be a muscle strain, and Dani Carvajal replaced him.
Villarreal had demonstrated earlier in the half that they could pose a threat and won a penalty when Ramos illegally blocked Manu Trigueros' shot after Raphael Varane had carelessly lost possession in his own half. The only question mark was whether Ramos was marginally outside the area when he handled it.
The visitors had missed their last two spot-kicks - Bruno culpable at Malaga and Alexandre Pato against Real Sociedad - but Bruno's kick could not have been more composed, beating Casilla with a Panenka-style chip down the middle in first-half stoppage time.
No penalty was given Real's way at the start of the half despite Ramos' claims that his shot had been blocked by a hand after Asenjo made a hash of gathering a free-kick into the box.
But the Spain defender did atone for conceding the penalty by equalising three minutes into the second period, rising above two defenders at the far post to nod Rodriguez's inswinging corner past Asenjo for his third goal of the season.
Real suddenly looked far more threatening than at any stage in the first period, with Ramos seemingly having abandoned defensive duties to keep Villarreal penned in their own half.
Ronaldo was unable to apply the final touch to Carvajal's dangerous ball across the six-yard box and Bale's side-footed curler left Asenjo flat-footed but was just wide of the goalkeeper's left-hand post.
The Welshman was brought off for Lucas Vazquez with 19 minutes to go, and Villarreal still looked entirely capable of being Bernabeu party-poopers on the counter-attack.
Toni Kroos tested Asenjo with a swerving 25-yard strike in the 80th minute and Alvaro Morata's downward header was tipped over as time to score a historic winner ebbed away.
There was another loud penalty shout from Ramos with four minutes to go as Roberto Soriano bundled into him from behind, but it was not given as Real dropped league points for the first time since a home defeat to Atletico Madrid on Feb. 27.