Saturday's FA Cup action provided shocks and Sunday's drama potentially has a few more as Watford travel to Millwall at The Den to begin the day's action.
The Premier League side travel to the League One outfit keen to avoid an upset in their midday kick-off and that clash is followed half-an-hour later by a Hull City side aiming to avoid being dumped out of two cups inside a week when they visit Fulham.
Sutton United will hope to become the second non-League team in the hat for the fifth round when they look to bring down Leeds United at Gander Green Lane.