Atletico Madrid outplayed city rivals Real Madrid to earn a 1-0 win on Sunday night that betrayed the wealth of chances created in the club's first La Liga victory in the capital derby since 2016.
While Real have the league sewn up - and only returned to training on Saturday after their European heroics - Atletico's Champions League qualification is far from secure. The hosts promptly played like the side with a purpose.
Within the opening eight minutes, Atletico squandered a pair of glorious chances by pressing the visitors high up the pitch as Angel Correa and Yannick Carrasco both failed to test Real's stand-in goalkeeper Andriy Lunin.
Atletico maintained their pressure, penning Real into their own half. Matheus Cunha had a shot blocked before sprinting towards the penalty box after another high turnover.
The Brazilian forward was sandwiched by Eder Militao and Jesus Vallejo as he dawdled while lining up a shot. But Cunha's hesitancy was rewarded with a penalty as a VAR review revealed Vallejo's clumsy challenge. Carrasco coolly converted to give Atletico a heartily deserved 40th-minute lead.
Real got out of their armchairs for the second half. Aided by Atletico easing off their press, the freshly-crowned champions committed swathes of white shirts forward.
Yet, this only left space behind Real which Atletico burst into but couldn't fully exploit. Carrasco whizzed a shot narrowly over the bar just minutes before Antoine Griezmann robbed Eduardo Camavinga on halfway. Driving forward, the half-time substitute teed up Cunha for a golden one-on-one only to see the Brazilian meekly roll a shot into Lunin's midriff.
Carlo Ancelotti made seven changes to the XI that so dramatically knocked out Manchester City in midweek. The steady introduction of these stellar names bolstered Real's flickering threat.
However, Atletico continued to carve out chances which they found new ways to miss. Griezmann missed the target twice in quick succession from a pair of shots inside the penalty before Carrasco hit the inside of the post. As Diego Simeone watched the ball agonisingly spin in front of the goal-line he turned to the heavens in despair.
El Cholo's prayers were answered as Atletico managed to hang onto a vital derby win that moved them six points clear of fifth-placed Real Betis with three games to go.
1. Atletico Madrid (4-4-2)
GK: Jan Oblak - 7/10 - Sharp reactions to Real's sporadic attempts at his goal.
RB: Sime Vrsaljko - 6/10 - Offering an option wide on the right which was regularly unused.
CB: Stefan Savic - 7/10 - Carried out what defensive work he had without much fuss.
CB: Jose Maria Gimenez - 6/10 - A little too eager to advance Atletico up the pitch at times.
LB: Reinildo - 7/10 - Held a solid, reserved position, staying back in support of his centre-backs rather than bombing forward on the overlap.
RM: Marcos Llorente - 6/10 - Drifting centrally, Llorente's lung-bursting surges around the pitch weren't always picked out but his teammates - much to his evident frustration.
CM: Geoffrey Kondogbia - 8/10 - Brilliant bullying off the ball but adept at punching a pass between the lines while in possession as well.
CM: Koke - 7/10 - Pushing onto the shoulder of the Real midfielder closest to receiving the ball, Koke played a subtle but crucial role in limiting the options his opponents had in possession.
LM: Yannick Carrasco - 8/10 - A repeat wriggling menace, Carrasco made up for his early squandering with a crisp penalty.
ST: Angel Correa - 5/10 - Faded from the game after wasting a clear sight of goal inside the first five minutes before getting hooked at half-time.
ST: Matheus Cunha - 6/10 - Lucky to win a penalty when he turned down presentable options but his direct running was a threat in that move and elsewhere.
SUB: Antoine Griezmann (46' for Correa) - 7/10 - Much more involved than Correa, Griezmann wreaked havoc with the ball at his feet - or rolled under his studs.
SUB: Felipe (73' for Reinildo) - 5/10
SUB: Rodrigo de Paul (89' for Cunha) - N/A
SUB: Renan Lodi (90+3' for Carrasco) - N/A
2. Real Madrid (4-3-3)
GK: Andriy Lunin - 7/10 - On his first-ever La Liga appearance for Real Madrid, Lunin started shakily but grew in confidence, making a great one-on-one save with Cunha in the second half.
RB: Lucas Vazquez - 4/10 - Struggled - as most would - against Carrasco in the form he found the Belgian in on Sunday night.
CB: Eder Militao - 5/10 - Forced into backing up Vazquez when the converted winger was caught up the pitch, Militao had a mixed (but better than Vazquez) time defending Carrasco.
CB: Jesus Vallejo - 3/10 - Constantly looked outnumbered even with teammates around him, needlessly trod on Cunha for the penalty after he had lost possession.
LB: Nacho Fernandez - 7/10 - Playing like an adventurous, orthodox left-back, the right-footed but versatile Nacho was tasked with providing Madrid's width down his flank in possession but was regularly back to help defensively.
CM: Eduardo Camavinga - 5/10 - Peppered the game with flashes of guile but struggled to stamp more of an influence on proceedings.
CM: Casemiro - 7/10 - Scuttling in front of Real's box superbly, how often Casemiro's imperious tap tackles and pinches of possession were required will have undoubtedly unnerved Carlo Ancelotti.
CM: Toni Kroos - 4/10 - Flustered and hurried, Kroos was particularly unsettled by Atletico's high press.
RW: Marco Asensio - 4/10 - Much like Real's opposite winger, Asensio played very narrowly when in possession, running into crowds and red and white.
ST: Luka Jovic - 4/10 - A last-minute replacement ahead of kick-off, Jovic almost had as many touches as he would have had on the bench.
LW: Rodrygo - 5/10 - Skirted around the fringes of the match, the Champions League saviour was sharp on the rare occasions he got the ball in the final third.
SUB: Vinicius Junior (61' for Jovic) - 6/10 - Added the thrust and trickery he has demonstrated all season.
SUB: Federico Valverde (61' for Casemiro) - 6/10 - Drove as the crow flies towards goal whenever he got on the ball, rattling off a flurry of shots that whistled near the goalframe.
SUB: Luka Modric (68' for Kroos) - 6/10
SUB: Ferland Mendy (69' for Militao) - 5/10