Real Madrid will head into a big week knowing the club's Spanish title bid is back on track and that one of its records will stand for at least another season.
Carlo Ancelotti's team will be just three points behind Barcelona ahead of next weekend's "Clasico" at Camp Nou after the La Liga champion dropped its first points this campaign in Saturday's 0-0 draw at Osasuna.
It was the first time in 64 league matches Barca had failed to score, despite the introduction of Lionel Messi midway through the second half.
Second-placed Atletico Madrid then surrendered the division's only other 100% record, losing 1-0 at Espanyol to also fall one win short of the 1968-69 Real side's benchmark beginning.
Ancelotti, meanwhile, was lifted by a 2-0 win at home to Malaga earlier in the day which lifted some of the building pressure on the Italian.
"Today I am happy, we have to keep going and keep improving, but the team has done well today, the week has started well," the former Milan and Chelsea coach said.
Angel Di Maria put Real ahead a minute into the second half and Cristiano Ronaldo sealed victory in time added on with a penalty after substitute Gareth Bale was brought down in the box.
Marquee signing Bale is now in contention to face Juventus in the European Champions League on Wednesday, having impressed on his return from injury.
"Bale has no problems and is another option. We will see now that we have three days of training before the next match," Ancelotti said.
He backed Ronaldo after the Portugal forward -- who hit the bar in the first half -- apologized to fans for not scoring earlier in the match.
"He was not happy because he wanted to score -- he had chances and I said that the today it was just not his day, but he showed a cool mind in scoring the penalty because when it is not your day, it is not difficult to miss a penalty," the 54-year-old added.
Barca coach Gerardo Martino shrugged off his side's frustrating day ahead of Tuesday's Champions League trip to Milan.
"We should have won given the chances we created. I'm pleased with the team's performance," the Argentine said.
"We weren't accurate in front of goal. In the first half we were missing that final pass. We were off by centimeters.
"I would be concerned if there had been a decline in our performance. We tied because that's how it had to be -- I don't think our level has dropped."
Atletico's perfect run came to an end in the Catalan capital as Espanyol triumphed thanks to a bizarre own-goal from goalkeeper Thibaut Courtois, who could only divert Juan Fuentes' 55th-minute cross into his own net via his outstretched foot.
Atletico did breach the opposition's goal, but Mario Suarez was offside when he headed in Koke's free-kick.
In Saturday's other La Liga game, Valencia missed a chance to stay in touch with the top four after losing 2-1 at home to Real Sociedad.
Bayern Munich returned to the top of the Bundesliga after coming from behind to beat Mainz 4-1, with substitute Mario Gotze inspiring a second-half fightback.
The 21-year-old set up Arjen Robben's equalizer and was also involved as Thomas Muller and Mario Mandzukic made it 3-1. Muller sealed the scoring with a penalty after Bastian Schweinsteiger was fouled.
It extended the German and European champion's unbeaten run to 34 matches, two short of Hamburg's longstanding league record.
Borussia Dortmund reclaimed second place with a 1-0 win at home to Hanover, thanks to Marco Reus' first-half penalty.
It gave last season's runner-up a goal-difference advantage over third-placed Bayer Leverkusen -- whose controversial Friday win against Hoffenheim, courtesy of a goal that went through the sidenetting, will be reviewed on Monday.
Fourth-placed Hertha Berlin, another seven points back, beat Borussia Moenchengladbach 1-0, while Schalke took fifth as Roman Neustaedter's injury-time goal earned a 3-2 win at bottom club Eintracht Braunschweig.