Defending La Liga champions Barcelona settled for a 0-0 draw against Osasuna , giving Atletico Madrid the opportunity to move the league summit with a victory over Espanyol on Saturday.
The Catalan giants opted to rest several first-team regulars ahead of Tuesday's Champions League trip to AC Milan, with Lionel Messi starting on the bench after his thigh injury and Gerard Pique, Dani Alves and Alexis Sanchez not included.
The visitors bossed possession and had the lion's share of chances - the best of which were passed up by Cesc Fabregas - but Osasuna held on to become the first team in La Liga to keep a clean sheet against Barca in almost two years.
The stalemate represented the first dropped points for Gerardo Martino's men this term, and meant they failed to equal the record of nine straight wins at the start of a season. It also gave Osasuna only their seventh point of the campaign.
Messi was named among the replacements for Barca, having missed two games for his club as well as Argentina's recent World Cup qualifiers due to a thigh injury, while Carles Puyol was handed his first start in seven months.
Osasuna's plans were dealt an early blow when midfielder Sisi Gonzalez was carried off on stretcher after just five minutes and had to be replaced by Manuel Onwu.
Barca dominated the first half, Neymar pulling the strings, but struggled to make an impact in the final third.
Neither goalkeeper was unduly troubled in the opening 45 minutes, a couple of long-distance attempts from Onwu and the same from Barca midfielder Andres Iniesta the most either side could muster early on.
Fabregas claimed he had been shoved after his attempted header from Martin Montoya's cross had skimmed wide off his left hand in the 32nd minute, but the referee was unmoved.
Marc Bartra should have put the visitors ahead in the 44th minute when he found himself unmarked from a corner but headed over from six yards.
Barca looked more lively at the start of the second half, at least creating openings more freely although still not challenging Osasuna goalkeeper Andres Fernandez.
Neymar was inches away from connecting with a low cross from Montoya after the overlapping full-back had been played in by Fabregas in the 54th minute.
Former Arsenal captain Fabregas then had a couple of fine chances of his own - and really should have done better. First he mis-hit an attempted lob straight into the grateful hands of Fernandez following a clever ball over the top from Neymar, and then he blasted over when even better placed thanks to Xavi's neat through-ball.
Fullbacks Adriano and Montoya were getting forward at every opportunity but the final ball was always just eluding a Barca touch, forcing Martino to shuffle his pack.
Messi was introduced in place of Xavi midway through the second half, with Cristian Tello on for Pedro Rodriguez eight minutes later.
Ballon d'Or winner Messi dragged a left-footed shot wide 12 minutes from time and was unable to get his shot away from close range when played in by a dink over the top soon after, but that was as close as he or anyone else came in the closing stages as the game petered out - much to the jubilation of the home fans and the disappointment of the visitors.