De Bruyne with low free-kick under the wall
Unmarked Sterling with header for second
Cardiff's Bennett booked for tackles on Sane & Diaz
FT: Chelsea 3-0 Newcastle
Fifth-round draw in the One Show on BBC One on Monday - 19:00 GMT
Cardiff 0-2 Manchester City
Neil Paterson's huge throw-in is cleared by Manchester City and Leroy Sane then just sprints past every Cardiff player.
He almost goes the whole way before Joe Bennett brings him down with a really nasty tackle.
He gets a yellow card but it maybe should have been a red.
Cardiff 0-2 Manchester City
Allow Twitter content?
This article contains content provided by Twitter. We ask for your permission before anything is loaded, as they may be using cookies and other technologies. You may want to read Twitter’s cookie policy, external and privacy policy, external before accepting. To view this content choose ‘accept and continue’.
App users may have to click link to view content...
Cardiff 0-2 Manchester City
Dafydd Pritchard
BBC Sport Wales at the Cardiff City Stadium
Manchester City's fans are enjoying this, singing about a trip to Wembley which would seem more than likely if they can maintain this sparkling form in the FA Cup.
This has been a masterclass, bossing possession and breaking at speed whenever Cardiff venture further than the halfway line.
Cardiff 0-2 Manchester City
Mark Lawrenson
BBC football expert on BBC One
It's a masterclass and there's no ego about it whatsoever. No one player wants to take the glory, they are all playing for one another.
Image source, ReutersCardiff 0-2 Manchester City
Marko Grujic plays a lovely diagonal pass over the top to David Hoilett but the Cardiff midfielder can't pick out a teammate in the box.
Man City then break forward with pace and Leroy Sane is just inches away from getting a shot away before Cardiff eventually get the ball into safety.
#bbcfacup or 81111 on text
That cross from Bernardo Silva was as good as, if not better than, the 'goal' he just scored. Justice.
Alex, London
I think he'd still like the goal though, Alex...
Cardiff 0-2 Manchester City
Steve Claridge
Ex-Premier League striker on BBC Radio 5 live
From a neutral perspective it's not what we wanted, but from a Manchester City perspective it's everything that they deserve. On the balance of play, you can't argue with the scoreline.
Cardiff 0-2 Manchester City
Bernardo Silva is popping up in all kinds of positions at the moment. He makes another darting run but he's called back for offside... just.
Cardiff try to play it forward quickly but their attack is broken down as Joe Ralls is beaten to the ball by Kyle Walker and Manchester City have a free-kick.
Cardiff 0-2 Manchester City
Mark Lawrenson
BBC football expert on BBC One
Sterling had oceans of space and time because the ball is played so early and with such pace that it's really a footballing lesson. No disrespect to Cardiff but teams will struggle to cope with this.
Image source, Reuters
Raheem Sterling
Oh, what a ball from Bernardo Silva.
He fires it in early from the left and it's got so much curl and pace on it, Raheem Sterling simply has to glance it towards goal and past Neil Etheridge.
Cardiff 0-1 Manchester City
Since that second disallowed goal, Manchester City have been driving forward and creating opportunities.
Kenneth Zahore remains as an outlet for Cardiff though but he loses out to Fernandinho by the corner flag.
Cardiff 0-1 Manchester City
As you may expect, Manchester City dominating the ball. Cardiff's direct play has helped them get plenty of territory though. They've had three shots so far to Manchester City's 10.
Image source, .Cardiff 0-1 Manchester City
#bbcfacup or 81111 on text
Dave: Referees having a tough weekend. Why was Man City's goal ruled out ? Player was not offside and keeper would not have saved it anyway regardless of the player possibly in his view!
Tom, Berkshire: This is madness. I said this yesterday, how can FA cup matches this year be legitimate when some matches have VAR and others don’t. Some teams could get through because of VAR and other teams out because of a lack of it. It is an unfair experiment.
John: I can see what the linesman is getting at, blocking the line of sight and all, but this is a bit of a mess by the officials and it's all getting out of hand. But they used VAR yesterday and got stick, no VAR today and get stick - they can't win but they don't help themselves.
Cardiff 0-1 Manchester City
This time Kenneth Zahore does well.
He's all on his own on the half-way line so he holds the ball up and earns his side a throw-in despite pressure from three Manchester City midfielders.
Cardiff 0-1 Manchester City
Sean Morrison cooly takes the ball off Raheem Sterling before playing a simple pass to Kenneth Zahore down the left wing.
Cardiff City throw players forward but Zahore can't get past Vincent Kompany and the attack is broken down.
Cardiff 0-1 Manchester City
Manchester City are still getting opportunities here.
It's Raheem Sterling who has an opportunity to shoot now but it's taken a deflection and is out for a corner.
#bbcfacup or 81111 on text
Dan, Smith: I hope all those pre-historic dinosaurs whinging about VAR yesterday aren't going to question Lee Mason and his linesman there?
Dan, London: Go on then, who’s gonna say that VAR would have helped that?!? If you had a spare twenty minutes I’m sure it would.
Steven: Wait... that was disallowed for what? Robbed of a very good goal there.
Nobody knows, Steven, nobody knows...
Cardiff 0-1 Manchester City
Mark Lawrenson
BBC football expert on BBC One
It was absolutely not offside. The game's gone.
Image source, Getty Images#bbcfacup
That didn't look offside to me.
What do you think? Let us know.