Zinedine Zidane’s double substitution at half-time transformed the Madrid derby on Saturday as Real Madrid edged past Atletico 1-0 to move six points clear at the top of La Liga.
Espanyol stayed three points from safety at the bottom of the standings.
Karim Benzema scored the winner at the Santiago Bernabeu after Zidane’s decisive intervention turned a contest that Atletico had dominated into another comfortable Real Madrid victory.
Vinicius Junior, one of the substitutes, was a key to the goal.
Second-place Barcelona can cut the gap back to three points by beating Levante at home on Sunday but Atletico now trail the leaders by 13 points.
While Diego Simeone’s side were excellent in the first half, they were yet again blunt in front of goal and then failed to respond when their opponents found a different gear.
This is Atletico’s fifth game without a win. The worry is that on this form, they should worry not about the title race but about missing out on Champions League qualification.
It is a far cry from pre-season when Atletico thrashed Real 7-3 and many were tipping them as serious challengers.
Zidane was under pressure then, but his team are on a relentless run, now 21 games unbeaten, the latest due in large part to his changes.
The decision to ditch a failing system and revert to 4-3-3, with Vinicuis Junior and Lucas Vazquez coming on for Isco and Toni Kroos, was both brave and effective.
Real’s form is impressive and they have Eden Hazard, out since November, on the brink of a return, perhaps on Thursday in the Copa del Rey quarter-finals against Real Sociedad.
Gareth Bale’s absence was not related to fitness. The Welshman was left out of the squad despite training for most of the week after an ankle injury.
Atletico were without the injured Kieran Trippier, meaning Sime Vrsaljko came in a right-back. January signing Yannick Carrasco was named on the bench, after rejoining from Dalian Yifang the day before.
Simeone’s side were significantly better in the first half and should have taken one of a handful of decent chances as Vitolo hit Thibaut Courtois, Saul Niguez flashed wide and Angel Correa poked past the post after going through one-on-one, even if he probably would have been called offside.
Real Madrid’s cluster of central midfielders looked unsure of their 4-3-2-1 shape. Fede Valverde looked particularly uncomfortable as he spent much of the first half as a right winger. Luka Modric was virtually anonymous in his more advanced role.
Zidane’s double change was a recognition of Atletico’s superiority as he reverted to the more familiar 4-3-3 with Modric deeper in midfield.
The balance shifted immediately. Real dominated the start of the second half.
In the 56th minute, Vinicius cut in from the left and slipped in the overlapping Ferland Mendy, whose cross to the back post gave Benzema a simple finish.
Atletico had been weakened shortly before when Alvaro Morata, perhaps the best player on the pitch in the first 45 minutes, went off with an injury. He was replaced by Thomas Lemar, whom Simeone expected to be sold in the January transfer window.
Real retreated a little, perhaps waiting for an Atletico push that never came.
Valverde enjoyed a spontaneous standing ovation for a burst forward, an appreciation too perhaps for his brilliant breakthrough season. Another roar of approval greeted the final whistle.
Meanwhile, Granada ended a two-game losing streak in the league by coming from behind to beat last-placed Espanyol 2-1 at home. The victory moved Granada to 10th place.
Agencies