LaLiga leaders Real Madrid stumbled to a frustrating 1-1 draw at neighbours Rayo Vallecano on Sunday.
Joselu fired the visitors in front early on but former Madrid youth player Raul de Tomas levelled for Rayo from the penalty spot in coach Inigo Perez's first match at the helm.
Carlo Ancelotti's side stretched their lead on Girona, second, to six points, before the Catalan minnows face Athletic Bilbao on Monday.
After Los Blancos thrashed Girona last weekend to take a five-point lead in the title race, the draw allows their closest pursuers a chance to cut the gap.
Dani Carvajal was sent off at the death for Madrid after appearing to elbow Kike Perez.
🏁 @RayoVallecano 1-1 @RealMadrid
— Real Madrid C.F. (@realmadrid) February 18, 2024
⚽ 5' @JoseluMato9
⚽ 27' Raúl de Tomás (p.)#RayoRealMadrid | #Emirates pic.twitter.com/JSBTaECbpv
"We have to win all our games, but to win a league, the games you can't win, you can't lose them (either)," Madrid coach Ancelotti told reporters.
"Sometimes draws can hurt a bit but it could be a positive step to take us closer to winning the league."
Real Madrid have suffered just one defeat in the top flight and are unbeaten in 19 league matches.
Rayo, 14th, sacked Francisco Rodriguez earlier this week and appointed Perez, with Madrid's visit a baptism of fire.
It took only three minutes for Madrid to take the lead, with Fede Valverde racing down the right on a sharp counter-attack.
The Uruguayan crossed for Joselu to bundle home and despite initially being called offside, VAR showed the goal should stand.
Joselu headed home a second but this time it was correctly disallowed after Lucas Vazquez had taken the ball out of play before crossing for his Spanish compatriot.
Despite taking an early lead, Madrid failed to create many clear openings.
Los Blancos were without top goalscorer Jude Bellingham, currently recovering from an ankle injury.
They earned a 1-0 win over RB Leipzig in the Champions League in midweek and perhaps tiredness told against an energised, hard-working Rayo.
DE TOMAS DELIVERS
The hosts pulled level through De Tomas's penalty after 27 minutes, slammed down the middle after Eduardo Camavinga handled Oscar Trejo's shot.
Valverde, heavily involved, cracked a shot against the post from 20 yards as Madrid looked to restore their lead.
At the other end Andriy Lunin was alert to save at the near post from Alvaro Garcia after Rayo picked Luka Modric's pocket.
Substitute Toni Kroos forced a good save from Rayo goalkeeper Stole Dimitrievski with a free-kick as the clock ticked down.
The Macedonian stopper also fielded a long range Carvajal drive in stoppage time.
The defender was then dismissed for swinging an elbow at Kike Perez in frustration after his shirt was pulled to earn a second yellow card and end a disappointing afternoon for Madrid.
We started very well, good with the ball, we scored, they ruled out another one marginally, Federico hit the post... until the penalty we did everything well," added Ancelotti.
Rayo have not won in seven matches across all competitions but will be proud of the draw.
De Tomas, brought into the team by Perez as a starter, was happy to score his first goal of the season, with Rayo midfielder Isi Palazon giving him the ball to take the spot kick.
"With the run we've been on this draw will do us a lot of good," De Tomas told Movistar.
"(Scoring) took a weight off me, I'm grateful Isi let me have the penalty knowing that I've gone a long time without scoring a goal."
Real Sociedad bounced back from Champions League last 16 first leg defeat by Paris Saint-Germain in midweek with a 2-1 win over Mallorca.
The Basque side moved provisionally sixth thanks to Mikel Merino's stoppage time winner.
Bottom of the table Almeria remain winless after relegation rivals Granada, 19th, held them to a 1-1 draw.