The two sides will replay at Stamford Bridge on Wednesday, January 16, after their 0-0 draw at Carrow Road on Saturday and, should Chelsea secure an expected victory, a mouth-watering London derby will take place on the weekend of Saturday, January 26.
It would be the first meeting between the two sides in the competition since the 1964-65 season, when Chelsea triumphed 1-0 at Upton Park to knock the holders out in, ironically, the fourth round.
In fact, there have only been three other contests between the west and east London rivals, and Chelsea won them all, in 1931, 1932 and 1946. Still, there is always a first time for everything!
Our only meeting with Norwich in the FA Cup came in the 1988-89 season, when a 0-0 draw in the quarter-final at Upton Park was followed by a 3-1 defeat at Carrow Road in the replay.
Says MD Paul Aldridge: "If you want to win the cup you have to go anywhere and beat anyone.
"But it will mean, if Chelsea go through, that we play them away twice in a matter of days because of the league game on January 20th."