Kevin De Bruyne emerged from the bench to score the winning goal, as Manchester City came from a goal down to survive an FA Cup scare against Leyton Orient. 

De Bruyne, along with fellow substitute Abdukodir Khusanov, netted after the break to cancel out Stefan Ortega's own-goal following Jamie Donley's stunning effort. 

Charlie Kelman registered Orient's first attempt on target in the 14th minute, showing great pace to speed past City debutant Vitor Reis, but seeing his effort smothered by Ortega. 

But two minutes later, Orient edged in front in sensational fashion when Donley's audacious effort from distance hit the underside of the crossbar, and bounced in off Ortega. 

Donley was then the hero at the other end, brilliantly clearing Bernardo Silva's strike off the line after the Portugal winger was picked out at the back post by Jack Grealish's dinked cross.

The Citizens were inches from finding a leveller in first-half stoppage time, but Omar Marmoush's close-range volley was kept out by an excellent Josh Keeley save. 

But Pep Guardiola's side drew level 11 minutes after the break when Rico Lewis' strike from the edge of the box deflected past Keeley, via a touch from substitute Khusanov. 

The visitors continued to turn the screw in their quest for a winner, with James McAtee clipping the post before Ilkay Gundogan forced Keeley into a smart save down low. 

However, with 11 minutes left, substitute De Bruyne sealed City's passage to the fifth round, prodding the ball home after collecting Grealish's pass in behind the Orient defence. 

Orient went agonisingly close to sending the game to extra-time, but captain Dan Happe could only fire over Ortega's crossbar from Tom James' inviting free-kick. 

Data Debrief: From Leyton to Madrid

With Real Madrid up next in the Champions League, City's preparations for their blockbuster clash were far from ideal, with Guardiola forced to turn to the quality on his bench to edge past the League One side. 

De Bruyne's telling contribution continued his fine run in the FA Cup. The Belgian has now been involved in 25 goals in his last 24 appearances in the competition, scoring eight and assisting 17.

Despite being pushed all the way, City have won their last 18 FA Cup matches against sides from a lower division, scoring 69 goals and conceding nine.

But they were forced to come from behind. Ortega’s own-goal was the first scored by a City goalkeeper in all competitions since Costel Pantilimon against West Bromwich Albion in December 2013.