The thrilling match was played in the shadow of a threat by Islamic State to target every quarter-final first leg, with a heavy security presence around the Santiago Bernabeu.
Spanish officials said 2,000 police were to be deployed, but the match was played without incident off the field. On it, there was plenty under the closed stadium roof, which produced a thunderous atmosphere.
Guardiola omitted influential playmaker Kevin De Bruyne after the Belgian said he was unwell shortly before the game, opting for Mateo Kovacic in midfield alongside Rodri Hernandez.
The former Barcelona coach also chose Stefan Ortega in goal over the experienced Ederson, only just back from a thigh injury, while Gvardiol overcame a fitness doubt to start.
Madrid coach Carlo Ancelotti opted for defensive midfielder Aurelien Tchouameni at centre-back over Nacho Fernandez and an early rash challenge from the Frenchman paved the way for City’s opener.
Tchouameni clumsily hacked down Jack Grealish after 33 seconds and was booked, meaning he will miss the second leg.
From the free-kick Silva punished Madrid further, catching goalkeeper Andriy Lunin out at his near post with a low effort which skidded home.
Lunin was sluggish to react and although he got a hand to the ball he could not keep it out.
Ancelotti, coaching a record 200th Champions League match, claimed his team lacked courage and personality when they were crushed by City in last seasons semis, but they showed mental strength to quickly turn the game on its head.
This kind of feat is Madrid’s wont in the Champions League, and they produced two goals in two minutes, reminiscent of their stunning 2022 semi-final comeback against City thanks to Rodrygo’s brace.
Dias deflected the first into his own net as he tried to block Camavinga’s long-range piledriver, and Rodrygo slipped home the second after Vinicius Junior played him in, aided by another deflection, off Manuel Akanji.
The Brazilian sliced wide at the end of a slick Madrid transition, aided by a Vinicius backheel, as Los Blancos demonstrated how dangerous they are on the counter-attack.
A breathless first 45 minutes was followed by more of the same, in a tie increasingly dubbed a Champions League “Clasico”.
Rodri headed over for the visitors and Vinicius blasted over the top before City sprang their own comeback and extended their unbeaten run to 26 matches.
Foden pulled his team level with a superb strike, arced into the top corner from the edge of the box.
The England international is enjoying his finest goalscoring campaign with this perfectly placed effort his 22nd across all competitions.
With Antonio Rudiger shackling Erling Haaland, City got a goal from an unlikely source to lead five minutes later.
Defender Gvardiol’s ferocious bending effort from distance left Lunin no chance and silenced the Bernabeu — but not for long.
Valverde’s brilliant volley from Vinicius’ cross zipped past Ortega to level the score and leave the game deliciously poised for the second leg on April 17.
© Agence France-Presse
Photo: Twitter @JacobsBen