2017-18: Eliminated by Liverpool 5-1 on aggregate in quarter-finals, lost first leg away 3-0, lost second leg at home 2-1.
Traumatised by the vicious reception from a huge mob of Liverpool fans who attacked the City team bus with missiles outside Anfield, Guardiola's team crumbled in the first leg.
Goals from Mohamed Salah, Alex Oxlade-Chamberlain and Sadio Mane put Liverpool three up by the 31st minute.
In the return in Manchester, City scored early on through Gabriel Jesus, but never built up enough momentum for a comeback as Salah and Roberto Firmino struck for the Reds after half-time.
2018-19: Eliminated by Tottenham on away goals in quarter-finals, lost first leg away 1-0, won second leg at home 4-3.
Handed a golden opportunity to take the lead in the first leg at the Tottenham Hotspur Stadium when Danny Rose's handball conceded a first half penalty, City blew it as Sergio Aguero's spot-kick was saved by Hugo Lloris.
Even an injury to Tottenham striker Harry Kane couldn't inspire Guardiola's side, who played a cautious game and were beaten by Son Heung-min's late goal.
Roaring into a 4-2 lead after trailing 2-1 in the second leg, City were heading for the semi-finals until disaster struck in the 73rd minute when Fernando Llorente bundled home despite a VAR review of a potential handball by the Tottenham striker.
In an incredible finish, Guardiola was punching the air in delight when Raheem Sterling fired what looked to be a last-gasp winner, only for VAR to rule it out for offside.