Watford dug deep to force a replay as Fulham failed to convert superiority into victory at Vicarage Road.

The Premiership visitors took the lead on 17 minutes when Zat Knight headed in a Mark Pembridge cross. Collins John and Steed Malbranque wasted chances to extend Fulham’s lead and Paul Devlin should have punished them ten minutes before the break but striker contrived to head wide from Hameur Bouazza’s cross. Watford did level just before the break when Andy D’Urso awarded a penalty after Liam Fontaine tripped Bouazza following a goalmouth scramble and Heidar Helguson coolly converted it.

The visitors spurned a number of clear chances in the second half. Luis Boa Morte, linked with a move to Newcastle last week, excelled for Fulham but veteran keeper Alex Chamberlain kept out efforts from Andy Cole and the lively Malbranque. After the Premier League side failed to make their dominance pay, van der Sar was forced into an excellent save from Gavin Mahon to prevent Ray Lewington from causing a serious Cup shock against his former club.

WATFORD (4-5-1): Chamberlain, Chambers, Cox, Demerit, Darlington; Devlin (Dyer 82), Gunnarsson, Mahon, Ardley (Webber 66), Bouazza (McNamee 76); Helguson. Subs (not used): Blizzard, Doyley.

GOAL: Helguson (pen 42).

FULHAM (4-4-2): van der Sar; Rosenior, Bocanegra, Fontaine, Knight; Legwinski (Clark 83), Pembridge, Malbranque, Boa Morte; Cole, John. Subs (not used): Crossley, Rehman, McBride.

BOOKED: Bocanegra.

GOAL: Knight (17).

REFEREE: Andy D’Urso (Essex).