Los Blancos were missing several key players including Kylian Mbappe but Uruguayan midfielder Valverde's stunning treble, netted inside a 22-minute spell, crushed Pep Guardiola's team at the Santiago Bernabeu.

Vinicius Junior missed a penalty in the second half as Madrid could have built further on their significant lead ahead of the second leg in Manchester next Tuesday.

Even though Madrid are the record 15-time winners, their sketchy form offered little reason to believe they would pull off such a dominant result in what has become a modern Champions League classic.

City, who won the competition for the first and only time in 2023, even beat Madrid in the league phase and have strengthened since then.

However the Spanish giants produced their most convincing display of the season just when it mattered most to leave the Premier League visitors stunned.

"(It was) incredible, you dream of nights like this," Valverde told Movistar.

"It's been a long time since I enjoyed a game like this. I'm really happy but above all because the team won."

Madrid coach Alvaro Arbeloa, shorn of injured stars Mbappe, Jude Bellingham and Rodrygo Goes among several others, started 18-year-old midfielder Thiago Pitarch after some recent bright displays.

Arbeloa said he was expecting a surprise or two from former Barca coach Guardiola, and the Catalan selected a particularly attacking line-up, seeking to capitalise on the frailties Madrid have exhibited this season.

Guardiola opted for only two central midfielders and left Phil Foden and Rayan Cherki on the bench. Antoine Semenyo and Marc Guehi made their Champions League debuts and for an all-too-brief period City seemed to be settling in at the Bernabeu.

Trent Alexander-Arnold did well to keep Erling Haaland at bay before Semenyo drew the first save from Madrid's Thibaut Courtois.

Madrid took the lead against the run of play when Courtois thumped a long ball down the pitch in Valverde's direction.

Nico O'Reilly misjudged it and the Madrid midfielder blazed through on goal. City goalkeeper Gianluigi Donnarumma came out to try and stop him but Valverde nipped around him and rolled home in the 20th minute.

Seven minutes later Madrid's captain struck again. Vinicius Junior fed the midfielder who coolly drilled past Donnarumma to double the hosts' lead.

- Best for last -

After a difficult first half of the season, consigned to playing at right-back mostly under Xabi Alonso, Arbeloa's arrival in January has unleashed Valverde.

The 27-year-old snatched a last-gasp winner at Celta Vigo in La Liga on Friday and said that victory was one which had raised the team's morale.

It appeared he was grasping for optimism ahead of the City clash in which most imagined Madrid to be underdogs, but Los Blancos played like a side who had found belief again.

Valverde completed a first career hat-trick before half-time with the best of his three strikes.

Valverde neatly flicked Brahim Diaz's pass over the helpless Guehi and then volleyed home with aplomb as the Bernabeu crowd roared in delight. Finally they saw a Madrid they recognised, dynamic and, above all, competitive.

Diaz nearly netted a fourth soon after half-time but Donnarumma denied him, with City continuing to struggle after the interval.

Vinicius should have, after the Italian goalkeeper brought him down in the box, but Donnarumma read the Brazilian's intentions and saved his low penalty.

Man City's top scorer Haaland was kept quiet all night by Madrid centre-backs Antonio Rudiger and Dean Huijsen, with Guardiola replacing him even while chasing a goal.

Instead City's best chance to pull one back fell to O'Reilly as Pitarch's focus waned, but Courtois made a stunning reaction save with his leg to deny him and secure a precious clean sheet.

"The games in Manchester are very tough... We have to go there as if it was 0-0 and work hard," added Valverde.

"You notice it when the team all works together, all for the same objective. We've shown that when the team works together we can achieve big things."