Jurgen Klopp's side claimed a famous victory to book their place in the semi-finals, with Mohamed Salah's record-breaking goal cancelling out Gabriel Jesus' early opener before Roberto Firmino struck the winner at the Etihad Stadium.
Trailing 3-0 from the first leg at Anfield and fresh from Saturday's bitter defeat to Manchester United, City made a lightning start in their quest for a famous comeback, with Jesus netting in only the second minute.
The home side totally dominated the first half but were denied a second by fine margins, with Bernardo Silva hitting the post and Leroy Sane seeing a goal harshly ruled out for offside.
Furious with referee Antonio Mateu Lahoz's decisions, Guardiola raced onto the pitch at half-time to confront the official and was promptly ordered to watch the remainder of the match from the stands.
Salah compounded City's frustrations with a simple finish 56 minutes in, becoming the first Liverpool player to score eight times in a single Champions League or European Cup season, and Firmino pounced on a Nicolas Otamendi error to seal their passage to the last four and match his team-mate's record tally.
50 – Mohamed Salah has been directly involved in 50 goals in all competitions this season (39 goals, 11 assists), 11 more than any other Premier League player. Relentless. pic.twitter.com/gdrkWBHKnA— OptaJoe (@OptaJoe) April 10, 2018
Raheem Sterling was restored to a supremely attacking City line-up, and he needed just two minutes to make a telling impact, albeit amid some controversy.
Referee Lahoz ignored Virgil van Dijk's appeal for a foul by Sterling, allowing the winger to race into space beyond the Liverpool defence and cut the ball back for Jesus, who rolled the ball home from the very area Van Dijk would have occupied.
City, backed by a vociferous home crowd, laid siege to the Liverpool goal in search of a second and were inches away when Bernardo Silva blasted an effort off the left-hand post.
Loris Karius had surprisingly little to do despite City's dominance, but he escaped repercussions for a poor punch when Sane was flagged offside after finishing from close range, even though the ball had bounced into his path off James Milner.
Guardiola ran onto the pitch to remonstrate with Lahoz after no stoppage time was played, prompting the Spanish official to send the City boss to the stands, and matters got worse for the home side 11 minutes after the restart.
A much more composed Liverpool worked the ball through to Sadio Mane, whose run into the box was stopped by Ederson only for the City keeper to lose the ball, giving Salah a simple chipped finish in front of the travelling fans.
With the cause looking lost for the hosts, Firmino robbed Otamendi on the edge of the area and stroked a low finish past Ederson to send the travelling fans into delirium and seal a miserable week for City.
Key Opta stats:
- Liverpool have reached the semi-final stage of the European Cup/Champions League for the 10th time – the only English team to have appeared in more are Manchester United (12).
- After reaching the Champions League semi-finals in each of his first seven seasons in the competition as manager with Barcelona and Bayern Munich, Pep Guardiola has failed to make this stage in both of his campaigns with City.
- Liverpool are the first team to beat a side managed by Pep Guardiola three times in a single season.
- Jurgen Klopp has beaten Pep Guardiola more often than any other manager (7 wins).
- Roberto Firmino and Mohamed Salah have both scored more goals in a single Champions League/European Cup campaign for Liverpool (8 each) than any other player in the club’s history.
- Liverpool have scored 33 goals in the Champions League this season – the most by an English side in a single campaign.