Real Madrid’s title hopes suffered a further setback after being held by ten-man rivals Atletico Madrid at the Bernabeu.
Jose Gimenez gave the visitors a shock lead, not long after Angel Correa had been sent off for elbowing Antonio Rudiger.
But teenager Alvaro Rodriguez earned Real a point with his first goal for the club.
The home side are seven points behind leaders Barcelona, who play on Sunday.
Carlo Ancelotti’s team dominated the first half but clear-cut openings were few and far between before the interval.
Marco Asensio stung Jan Oblak’s palms at one end, before Yannick Carrasco shot straight at Thibaut Courtois at the other as both sides struggled to make the breakthrough.
The game sparked into life in the second half when half-time substitute Correa was shown a straight red card after catching Rudiger in the chest with a flailing arm.
As Real struggled to press home their numerical advantage, substitute Gimenez nodded Antoine Griezmann’s free-kick into the corner to leave the visitors minutes away from a first victory at the Bernabeu since 2016.
But Rodriguez rose highest to head Luka Modric’s corner past Oblak with five minutes remaining, becoming the youngest player to score in a Madrid derby in the 21st century.
Eduardo Camavinga tested Oblak in the closing stages, but Atletico held on to move two points clear of fifth-placed Real Betis.
Barcelona can open a ten-point lead at the top of La Liga with victory at Almeria on Sunday.
The game was Diego Simeone’s 612th as Atletico manager in all competitions – equalling the late Luis Aragones’ club record.
Atletico confirmed after the game that left-back Reinildo suffered an anterior cruciate ligament rupture in a first-half collision with Federico Valverde, likely ruling him out for the rest of the season.