Graham Westley spurned a great chance to get United off to a flying start in just the 3rd minute when he fired a penalty against a post and forced a great save from Rocks keeper Colin Matthews in the 21st minute.
The hosts eventually took the lead in the 42nd minute when a long ball over the top found debutant Mark Mallinson who made a punching run down the left before finding John Lawford in the area, who chipped to the far post for the unmarked Cliff Hercules to head home his 16th goal of the season.
The Ducks always always looked the more likely of the sides to score and it was 2-0 in the 70th minute when a clever back heel by Westley released Lawford down the flank and he crossed to the near post for Hercules to skillfully steer the ball past Matthews.
Bognor never really seriously threatened but they came close to pulling a goal back in the 78th minute when Lee Gosling's superb pass opened up the United defence to find Nick Torpey but Ducks keeper Simon Gregory raced off his line to block the Bognor man's shot.
David Figg