Karim Benzema missed a penalty for Real Madrid as they finally blinked in the La Liga title race, dropping their first points of the season in a 1-1 draw with Osasuna on Sunday.
Elsewhere Real Sociedad won 5-3 at Girona and high-flying Real Betis fell to a 1-0 defeat at Celta Vigo.
After Barcelona beat Real Mallorca on Saturday, Madrid knew they had to win to stay top but were frustrated by Jagoba Arrasate's well-organised side at the Santiago Bernabeu.
Benzema, on his return to the side after injury, won a spot-kick but then fired it against the crossbar, and also had a goal disallowed for offside as Madrid tried to force a way through.
Vinicius Junior broke the deadlock just before half-time with a cross that snuck all the way into the far corner, but Kike Garcia's well-taken header early in the second period earned Osasuna a point.
"What we were missing was scoring that penalty, normally Karim scores them," Madrid coach Carlo Ancelotti told DAZN.
"He had no problem playing the 90 minutes. It's been a month since he's played, he has to get his best form back. He did his part, he had the chance from the penalty. It's an accident, sometimes it happens."
Real Madrid president Florentino Perez told the club's fans at an assembly on Sunday morning that a European Super League project was essential, but Osasuna showed domestic football can still offer a significant challenge.
Benzema made his first appearance since September 6, while Andriy Lunin and Dani Ceballos started in place of injured duo Thibaut Courtois and Luka Modric.
Madrid probed promisingly down the flanks, while at the other end Abde Ezzalzouli, on loan at Osasuna from Barcelona, crashed a shot into the side netting on a bright display.
Madrid opened the scoring in fortuitous fashion, with Vinicius whipping in a low cross which caught out goalkeeper Sergio Herrera and crept in at the far post.
Osasuna complained that Benzema and Antonio Rudiger were offside and interfering with play, but their protests were dismissed.
The visitors were level five minutes into the second half, when Kike Garcia brilliantly looped a backwards header over Lunin.
The goal meant Madrid have failed to keep a clean sheet in any of the first seven league games.
"We were quite solid at the back," insisted Ancelotti. "We conceded a goal from a deep cross, it was quite strange. The team was balanced, the objective is always to be strong to avoid conceding."