Fulham coasted through to the fourth round against a lacklustre Birmingham, who showed none of the fire which brought them a 1-0 win on this same ground a month ago.
There were times when it looked as if Clinton Morrison's mum would have defended better for the Blues as the second half became little more than a Sunday afternoon stroll for the Londoners.
Fulham caught Birmingham cold when Steed Malbranque broke from the halfway line in the 11th minute and with a man spare on either side of him the midfielder elected to free Facundo Sava on the left who took three paces forward before firing a low left foot drive which Nico Vaesen got a hand to, only to watch the ball roll slowly over the line.
City hit back when Martin Grainger arrowed a low free-kick from the edge of the box only to see Maik Taylor tip the ball around the post for a corner.
It was a rare effort for the away team as Fulham swept forward and it was no surprise when they doubled their lead on 23 minutes. Bjarne Goldbaek was first to a loose ball on the edge of the box and shrugged off two defenders to hammer a low drive beyond Vaesen's right hand and into the corner.
Any hopes Birmingham had of saving the day were blown away 50 seconds into the second half when the Blues half hearted tackles on first Malbranque and then Sava set up a chance for Louis Saha to score his first goal since the opening day of the season.
The striker, back from injury, made space for himself 15 yards out and despite two defenders breathing down his neck turned and fired past a stranded keeper.
Although Birmingham had two half chances in the last 10 minutes Fulham hit the post through Saha and then Sean Davis rattled the woodwork with the rebound.
The consolation from Stern John, who hooked in an injury time effort from 12 yards, was only their second shot on target throughout the 90 minutes.