Manchester City 2 Chelsea 0
Goals from Stevan Jovetic and Samir Nasri sent below-par Chelsea out of the FA Cup.
Jovetic fired home in the 16th minute and Nasri sealed Manchester City’s place in the quarter-finals by scoring midway through the second half.
Chelsea were handed a boost when Gary Cahill was passed fit for a game he was expected to miss with a calf problem.
Cahill played well but his team still looked vulnerable at the back without skipper John Terry, as City gained some revenge for the Blues’ potentially crucial recent league victory at the Etihad Stadium.
A minute after hitting the bar with his follow-up after keeper Petr Cech had spilled Yaya Toure’s shot, Jovetic put the home side ahead.
He got away from Cesar Azpilicueta to collect Edin Dzeko’s pass before firing through the Chelsea’s defender’s legs and in off the far post.
Keeper Costel Pantilimon fumbled Branislav Ivanovic’s cross and recovered quickly enough to prevent an equaliser, but otherwise Chelsea rarely looked like levelling.
Boss Jose Mourinho brought on Mohamed Salah at the interval and Fernando Torres on the hour mark, but the Premier League leaders still struggled to create clear-cut chances.
And they went further behind when Nasri tapped in after exchanging passes with David Silva, who looked offside.
Joleon Lescott was certainly offside before netting from close range after Cech had parried Javi Garcia’s header, so City were rightly denied a third goal.
Chelsea (4-2-3-1): Cech; Ivanovic, Cahill, Luiz, Azpilicueta; Mikel, Matic; Ramires (Torres 61), Willian (Oscar 70), Hazard; Eto’o (Salah 45).
Subs not used: Schwarzer, Lampard, Cole, Schurrle.