Match ends, Manchester City 5, Monaco 3.
Manchester City came from behind twice to secure a crucial two-goal advantage after a classic Champions League last-16 tie against Monaco at Etihad Stadium.
On a night of fluctuating fortunes and thrilling football, Pep Guardiola's side were on the precipice in this tournament before dragging themselves back to ensure they go into the return in Monaco with a priceless lead.
Raheem Sterling gave Manchester City a 26th-minute advantage after fine work by Leroy Sane but Monaco proved their threat to lead before half-time through Radamel Falcao's header and Kylian Mbappe's powerful rising drive.
Falcao then saw a penalty saved by Willy Caballero just after the break before Monaco keeper Danijel Subasic's blunder gave Sergio Aguero his first goal.
Colombian Falcao, back to his best after failed loan spells at Manchester United and Chelsea, then lifted a brilliant chip over Caballero to put Monaco back in front - but this was the signal for City to launch an enthralling attacking salvo.
Aguero - who felt he was denied a first-half penalty after he tumbled under a challenge from Subasic - volleyed in another equaliser before John Stones made amends for poor defending in the build-up to Falcao's second by putting City ahead on the night with a sliding finish at the far post after 77 minutes.
Man of the match Sane handed City that two-goal cushion with a simple tap-in from Aguero's pass eight minutes from time - but Monaco's vibrant attacking ambition means this tie is far from over.
Aguero's Manchester City future has been the subject of debate with recent arrival Gabriel Jesus appearing to find greater favour with manager Guardiola - but how can they seriously consider life without this world-class striker?
City may have been rattling at the back but Aguero was in magnificent form throughout, terrorising Monaco with his prodigious work-rate and sheer menace.
Aguero was denied a penalty in the first half when he was booked for diving after he was upended by Monaco keeper Subasic but he was not to be denied and was a key component of City's enthralling fightback.
He enjoyed some deserved good fortune when his shot went straight through Subasic for his first goal but he delivered a sumptuous right-foot volley to make it 3-3 and then set up Sane for the crucial fifth goal that gave City that two-goal advantage.
Aguero was substituted to a standing ovation and a kiss on top of the head from his manager with four minutes left - this was the night he delivered proof, as if it were needed, that he is the man City and Guardiola cannot do without.
Falcao posts warning signs for Man City
Falcao looked a lost soul in two seasons on loan from Monaco to Manchester United and Chelsea - but this was a master striker back to his best.
The Colombian marred his display with a horribly hesitant penalty that was saved by Caballero and would have put Monaco 3-1 up, but there was so much about his and the visitors' display to admire.
Falcao looked nothing like the demoralised figure who made 26 league appearances for United, scoring only four goals, and who got one goal in 10 league games for Chelsea.
He pounced like the poacher supreme to head his first but his second was a work of the striker's art, dismissing Stones from his presence before having the composure and class to deliver a lofted finish that left Caballero helpless.
And in those moments, he and Monaco delivered the message to Manchester City that this tie is not over. Monaco looked a side packed with threat and goals and they will still feel they can claw this back.
Mbappe has the sleek elegance of a young Thierry Henry while Bernardo Silva is a player of the highest quality. Monaco still represent a danger.
Man City's flaws exposed
Manchester City deservedly celebrated at the final whistle, the moment of triumph after a demonstration of resilience and attacking verve that brought a memorable win.
Guardiola, however, will not be fooled - and his agitated body language was a giveaway when it came to their defensive frailties.
Caballero helped Monaco equalise with poor distribution and Mbappe's second was the result of routine long ball. Stones was too weak in the physical exchanges with Falcao for Monaco's third.
And throughout, Nicolas Otamendi cut a nervous, uncertain figure whose weaknesses were probed relentlessly by Monaco.
Manchester City are in the driving seat - but they will need to make sure the back doors are firmly locked in the return leg in Monaco.
Man of the Match - Leroy Sane (Manchester City)
What they said
Manchester City manager Pep Guardiola: "I am so happy for the result, we are still alive. These kind of things help this club to achieve another step. We attacked in small spaces. That's why they wanted me to come here. Everybody has to be congratulated.
"We are going to fly to Monaco to score as many goals as possible. If we don't score in Monaco we will be eliminated."
Monaco boss Leonardo Jardim: "It was perhaps one of the most exciting games of this year's Champions League. A great game of football.
"The key to the game was the missed penalty to make it 3-1 but there's 90 minutes with us. Nothing is finished."
Monaco lead the scoring charts - the stats
- Manchester City scored five goals in a Champions League game for just the second time (the other was 5-2 v CSKA Moscow in 2013, excluding qualifiers).
- This game is the first time eight goals have been scored in the first leg of a Champions League knockout game.
- Raheem Sterling has had a hand in 10 goals in his past nine Champions League starts (five goals, five assists).
- Kylian Mbappe is the second youngest French scorer in the Champions League, following Karim Benzema (17 years 352 days) who scored for Lyon against Rosenborg in December 2005.
- Falcao scored as many goals at the Etihad (two) as he managed in 15 appearances at Old Trafford for Manchester United.
- Fabinho assisted more goals (two) than he had in his previous 15 appearances in the Champions League (one).
- Sergio Aguero's first goal was Manchester City's 200th European goal (203 at the end of this game). He has scored five goals in his last three Champions League games at the Etihad.
- Manchester City have saved each of their past five penalties in the Champions League (two from Caballero, three from Joe Hart).
- Monaco are the highest scorers in the top five European leagues this season in all competitions with 111 goals.
- There were 10 yellow cards handed out - the most in a Champions League game this season.
Manchester City are not in action this weekend because Manchester United's involvement in the EFL Cup final has led to the Manchester derby being postponed, so the Blues' next game is an FA Cup fifth-round replay with Huddersfield at the Etihad Stadium on Wednesday, 1 March.
Monaco, meanwhile, travel to Guingamp on Saturday looking strengthen their place at the top of Ligue 1.
- 30OtamendiBooked at 49mins
- 25FernandinhoBooked at 40minsSubstituted forZabaletaat 62'minutesBooked at 73mins
- 42Y Touré
- 7SterlingSubstituted forNavasat 89'minutes
- 17De Bruyne
- 10AgüeroBooked at 35minsSubstituted forRegesat 87'minutes
- 19SidibeBooked at 25mins
- 25GlikBooked at 8mins
- 10Bernardo SilvaBooked at 76minsSubstituted forJoão Moutinhoat 84'minutes
- 2FabinhoBooked at 81mins
- 14BakayokoBooked at 55minsSubstituted forDirarat 88'minutes
- 9FalcaoBooked at 67mins
- 29MbappeSubstituted forGermainat 79'minutes
- 8João Moutinho
- 16De Sanctis
- Antonio Miguel Mateu Lahoz
- Shots on Target
Second Half ends, Manchester City 5, Monaco 3.
Foul by Fernando (Manchester City).
Falcao (Monaco) wins a free kick in the defensive half.
David Silva (Manchester City) wins a free kick in the attacking half.
Foul by Fabinho (Monaco).
Kevin De Bruyne (Manchester City) wins a free kick on the left wing.
Foul by Djibril Sidibe (Monaco).
Substitution, Manchester City. Jesús Navas replaces Raheem Sterling.
Hand ball by Kevin De Bruyne (Manchester City).
Substitution, Monaco. Nabil Dirar replaces Tiemoué Bakayoko.
Foul by Fernando (Manchester City).
Benjamin Mendy (Monaco) wins a free kick on the left wing.
Substitution, Manchester City. Fernando replaces Sergio Agüero.
Corner, Monaco. Conceded by Pablo Zabaleta.
Attempt blocked. Fabinho (Monaco) right footed shot from outside the box is blocked.
Substitution, Monaco. João Moutinho replaces Bernardo Silva.
Foul by David Silva (Manchester City).
Bernardo Silva (Monaco) wins a free kick in the attacking half.
Attempt saved. Falcao (Monaco) left footed shot from the centre of the box is saved in the bottom left corner. Assisted by Benjamin Mendy.