Rugby took the lead in the 11th minute when Danny Martin's driven cross was clipped onto the bar by Mark Rosegreen and when Ducks defender Naseem Bashir tried to clear the rebound from under his own bar, he only succeeded in hoofing the ball into his own net.
It was 2-0 in the 58th minute when Darren Dickson's cross was laid back by Rosegreen to sub Matt Owen who fired past Ducks keeper Paul O'Reilly within a minute of coming on.
United pulled one back in the 76th minute when Steve Heard drove a 20 yarder past VS keeper Paul Batchelor and in off a post but it wasn't enough and Steve Ketteridge's side were out.
David Figg