Real Madrid's hopes of retaining the La Liga title were dented Sunday as the champions lost 1-0 at Real Mallorca, to remain five points behind leaders Barcelona.
The Catalans host Sevilla later on and can open up an eight point lead after a frustrated Madrid fell short against Javier Aguirre's side, with Marco Asensio missing a penalty against his former club.
Nacho's 13th minute looping header into his own net separated the teams in a hard-fought clash, frequently slowed by various fouls from the hosts.
Amid a constant battle between winger Vinicius Junior and Mallorca's players and supporters, the islanders held off Los Blancos to record an impressive victory.
"It was difficult because of the kick-off time, the opponent, it all gets complicated when they go in front," Nacho told Movistar.
"They were lucky with the goal, and we also missed a penalty."
Vinicius suffered 10 fouls and Mallorca committed 29 in total.
"I think there's an atmosphere developing around Vinicius that doesn't favour anybody, not the player, not football, not the fans, who in the end get involved with the kid," added Nacho.
"Between us all we have to enjoy football which is a beautiful sport -- we have to leave controversies and nonsense to one side."
Real Madrid were without goalkeeper Thibaut Courtois, hurt during the warm-up, along with the injured Karim Benzema, Eder Militao and Ferland Mendy, among other absentees.
Rodrygo started up front in place of Benzema, while Dani Ceballos and Fede Valverde were given starts in midfield ahead of veterans Toni Kroos and Luka Modric.
The match was heated from the start, largely due to historic bad blood between Vinicius and Mallorca.
Mallorca captain Antonio Raillo has criticised the Brazilian winger on multiple occasions for lacking respect towards opponents and said he wouldn't hold him up as an example to his son.
Home fans at the Visit Mallorca Stadium whistled Vinicius when he was on the ball and chanted Raillo's name.
Ancelotti was also frustrated his team were playing in the early afternoon after having faced Valencia on Thursday night and Madrid started sluggishly.
Mallorca took an early lead when Nacho's attempted header sent Dani Rodriguez's in-swinging cross from the left looping over Courtois's stand-in Andriy Lunin and dipping just under the crossbar.
Nacho was under pressure from Mallorca target man Vedat Muriqi, who initially appeared to have scored the goal.
"It's been six games since I scored but I don't care that it's not mine, if we win, I don't care," said Muriqi.
The hosts shackled Vinicius well in the first half and reduced Madrid to pot-shots from distance, Antonio Rudiger and Valverde firing wildly off-target.
Vinicius was booked for stepping on Pablo Maffeo's foot, leaving the Brazilian incredulous after various fouls against him had not been punished with a card.
Ceballos protested vehemently to the officials as the teams went in at the break and was also booked, as temperatures rose in the Mallorcan sun.
- Heated -
Vinicius pulled at the Madrid badge on his shirt while looking at the home fans to agitate them further.
Early in the second half Raillo responded by offering Vinicius the Mallorca badge on his shirt to kiss.
Madrid had a golden chance to level when Mallorca goalkeeper Predrag Rajkovic brought down Vinicius, but the Serbian denied Asensio from the spot.
The Real Madrid forward tried to find the bottom right corner but Rajkovic flung himself full-length to tip away his penalty.
David Alaba returned from injury off the bench and his cross was volleyed narrowly over by Mariano Diaz, on a rare outing for the Dominican Republic striker, as Madrid's desperation grew.
Rudiger sent a dipping header wide late in stoppage time as Madrid's last chance slipped away.
Madrid will have to put defeat behind them quickly as they travel to Morocco midweek to take part in the Club World Cup.