Use play icon to watch live coverage alongside commentary from Seb Hutchinson & Efan Ekoku
Also listen to commentary from BBC Radio London
West Ham are seventh in the Premier League, Doncaster are fourth in League One
Three-time winners West Ham last won cup in 1980
Doncaster reached round five last season - equalling their best run in the competition
West Ham beat Stockport in round three, Doncaster overcame Blackburn
Ferran Torres
And one more late on.
Stepovers from Joao Cancelo then releasing Ilkay Gundogan, who cuts the ball back for Ferran Torres to convert into an open net from a couple of yards out.
Job done.
#bbcfootball or text 81111 (UK only)
Rob Elmore: The FA Cup's been brilliant to watch these last few weeks. It's prestige is back to how it used to be.
Andy Dufrain: Ben Tozer to the prem in January?
Matt Dawson: Absolutely gutted for Cheltenham.
Cheltenham 1-2 Man City
Andy Reid
Ex-Republic of Ireland midfielder on BBC Radio 5 Live
Cheltenham can be really proud, they've given everything and shown their quality at times. They've tried to play the ball when they can and they will take a lot of confidence from this.
Cheltenham 1-2 Man City
You could say Cheltenham lost their pizzazz after the withdrawal of Finn Azaz.
City equalised a few seconds after he came off.
Cheltenham 1-2 Man City
FOUR minutes added on.
Cheltenham 1-2 Man City
Now time is ticking away for Cheltenham.
Ohh, what could have been.
:-(
Cheltenham 1-2 Man City
Alex Addai on for Chris Clements with a few minutes remaining.
Cheltenham 1-2 Man City
And this was the chance for the equaliser.
Chris Clements sends in a corner which is flicked on and Matty Blair smashes the volley over from 12 yards.
Just could not keep it down and I don't think they'll get a better opportunity than that.
Cheltenham 1-2 Man City
Danny Murphy
Former Liverpool and England midfielder on BBC One
Brilliant pass from Fernandinho - Cheltenham are looking for offside but they're not going to get it. There's the run from Gabriel Jesus, great touch and put the miss to bed with that finish. VAR would possibly give that offside, maybe they've got away with one but what a touch that is.
Cheltenham 1-2 Man City
Cheltenham were complaining about an offside but he wasn't.
Gabriel Jesus
Two goals in the space of two minutes.
Cheltenham defenders fall asleep as Fernandinho's lofted ball over the top is taken down expertly by Gabriel Jesus in the box.
The Brazilian spins and strikes an emphatic finish which goalkeeper Josh Griffiths had no chance with.
Cheltenham hearts are broken late on.
Cheltenham 1-1 Man City
Danny Murphy
Former Liverpool and England midfielder on BBC One
Well if anyone was going to score it's him - he's been the one probing in this second half. Got himself in there, Joao Cancelo with the cross, Phil Foden's definitely onside. He has deserved that goal, he's been City's most creative player. Watched it come down, gently caressed it into the goal, good finish.
Phil Foden
Late leveller from City.
Sub Joao Cancelo curls a cross to the back post, Sean Long cannot get back and Phil Foden ghosts in to volley home.
If any City player was going to score, it was going to be him.
Ah.
Cheltenham 1-0 Man City
Finn Azaz off for the hosts and on comes Andy Williams.
Cheltenham 1-0 Man City
Final 10 minutes.
The biggest 10 minutes of some of these Cheltenham players' lives.
Here's the moment when Alfie May gave Cheltenham Town the chance of causing a huge upset.
Can they hang on?
Cheltenham 1-0 Man City
Joao Cancelo tries one from a long way out, nope not like that.
Time ticking away for City.
Cheltenham 1-0 Man City
Phil Foden heads over.
He's not going to score like that, is he!
#bbcfootball or text 81111 (UK only)
Just thinking back on all those comments after the draw about how "easy" City always have it.
Josh - Cheltenham fan for the day
I'm a City fan, is it wrong to want Cheltenham to win? Loving the Chairman at half time and the spirit his team are playing with...
Peter in Somerset