Real Madrid's Thibaut Courtois came back to haunt Atletico Madrid as two crunch saves denied Antoine Griezmann and Diego Costa on Saturday in a goalless draw at the Santiago Bernabeu.
Courtois spent three seasons at Atletico on loan from Chelsea but this was his first Madrid derby for Real. He made the most of it, saving when both Griezmann and Costa had only the Belgian to beat.
Gareth Bale could have won a pulsating encounter for Real too but he sidefooted wide from close range towards the end of the first half.
Bale did not emerge for the second period, substituted with a thigh injury, which will be a major concern for coach Julen Lopetegui. Real play CSKA Moscow in the Champions League on Tuesday.
In the end, both teams could have claimed victory but neither was perhaps too disappointed with a point.
Atletico maintain their resurgence after a miserable start while Real steady the ship following their hammering at Sevilla on Wednesday.
Lopetegui's side move back level with Barcelona on points. Atletico sit just two behind.
"We have not won because we didn't score but overall we have been very superior," Lopetegui said.
"The match was intense," added Diego Simeone. "We had chances through Griezmann and Costa but they were saved by Courtois.
"It's a pity because we wanted to win but we leave with a good result."
This match was not lacking for sub-plots. Courtois had played seven Madrid derbies for Atletico but now he was in the other team's goal.
It was Julen Lopetegui's first derby as Real coach, although he was the fifth Real manager Diego Simeone had stood opposite.
And Griezmann was up against Sergio Ramos, who very publicly slapped down the Frenchman's Ballon d'Or ambitions earlier this month. Perhaps Real took added satisfaction in presenting Luka Modric with his FIFA Best Men's Player award before kick-off.
Front and centre, however, was the battle at the top of the table. Only one of the last six La Liga matches played by Real and Barca had ended with them winning, which had pulled Atleti back in the race.
A blistering opening period was a blur of scuffles, mistakes and missed chances, with Atletico shading the start and Real the finish.
Griezmann attempted an audacious volley that flew over and then came his team's best chance when he only had Courtois to beat. His chipped finish met the goalkeeper's forehead.
Tempers flared as a sprinting Bale was shouldered out of play by Saul Niguez. Bale should have had the perfect riposte but sidefooted wide from two yards.
Ramos also left the pitch, voluntarily, for a bleeding eyebrow and Diego Godin managed briefly to halt play while trying to persuade Juan Martinez Munuera to consult VAR. The ball had struck Casemiro's arm but Godin was being optimistic.
Courtois frustrated Costa too, a jabbed finish blocked from the angle, while Jan Oblak almost gave a gift to Marco Asensio but the intercepting touch fell straight back into his hands.
Atletico had been relieved to reach half-time - Simeone had even poked a second ball onto the pitch to disrupt Real's rhythm - but the match simmered after the restart.
Bale had gone off for Dani Ceballos and it took until close to the hour before Asensio latched onto Toni Kroos' through ball. Oblak stook tall again.
Both sides tightened towards the end as Costa, Thomas Lemar and Luka Modric all made way. Neither team celebrated the final whistle but they did not seem too dissatisfied either.