Real Madrid allowed Barcelona to take an advantage into LaLiga's mid-season break after Athletic Bilbao held them to a second goalless draw in a week.
Following Wednesday's stalemate at Camp Nou in El Clasico, Zinedine Zidane's men drew a blank once more against their obdurate Basque opponents.
Toni Kroos and Nacho hit the crossbar either side of half-time and substitute Luka Jovic struck the base of the post with four minutes to play.
Champions Barca lead their great rivals by two points after 18 matches, having dispatched Alaves 4-1 on Saturday, while Athletic edge up to seventh and remain firmly in the European hunt
Rodrygo Goes and Vinicius Jr leant a vibrant edge to the Madrid attack during the opening exchanges, with the latter denied by the boot of Athletic goalkeeper Unai Simon at the end of a slaloming run.
The visitors allowed Kroos to saunter into the box on the end of Ferland Mendy's 19th-minute pass, the Germany midfielder cracking a shot against the crossbar from close quarters.
Athletic served notice of their threat a few moments later when Raul Garcia seized upon an unusually slack pass from Federico Valverde and sent Inaki Williams haring past Eder Militao. Thibaut Courtois was equal to the task at his near post.
Simon held a Karim Benzema header from Rodrygo's cross late in the first half and the Athletic keeper was grateful to see his bar frustrate Madrid once more before the hour.
Nacho rose highest to Kroos' right-wing delivery but could not direct his powerful effort downwards.
Simon plunged to keep out Benzema's angled 64th-minute shot, shortly after Gareth Bale replaced Rodrygo.
But it was another replacement, Jovic, who came closest to a winner - Simon looking on dejectedly, only for the Serbia forward's header to loop down against his upright.
What does it mean? Shot shy Madrid paying the price in the title race
There is little to choose between Barcelona and Real Madrid in terms of points as LaLiga heads into recess. However, the difference in terms of goals scored is 14 in Barca's favour and those deficiencies could tell dearly down the stretch for a Madrid team who have only lost once in the top flight this term but now drawn seven times.
Simon says, no way through
Even allowing for the fact Madrid's attack is not the potent force it once was, Athletic still needed a superb showing from their last line of defence. The latest goalkeeper off the production line that yielded Kepa Arrizabalaga, the 22-year-old Simon was near-faultless and deserved his moments of fortune.
Clock ticking on the Modric-Kroos axis
Real Madrid's engine room boasts two of the finest midfield talents of this decade in European football. As is customary, Kroos and his old ally Luka Modric were easy on the eye in a manner that sometimes becalmed the Santiago Bernabeu's mounting frustration. Nevertheless, it is hard to escape the conclusion that this Madrid need more dynamism and goal threat from deep and an interesting January beckons as those Paul Pogba rumours refuse to abate.
Madrid return to action on January 4 with a short trip to Getafe, while Athletic open 2020 against another of the division's high flyers, Sevilla.