Worcester will now entertain Brive in the last eight in April and Director of Rugby Ruddock claims in will be a cup cracker.
"The home quarter-final is a big prize for us and it is fantastic for the players," he said.
"It saves having to go somewhere like Brive where they have a number of excellent players, guys like Popham, Goode and Cohen.
"To go out to France and face them would have been a lot more difficult then here at Sixways Stadium.
"It will still be incredibly tough but it is what we wanted. From a business perspective it is good for us and we can sell the commercial side in the knock out stages.
"Once you get to a knock out stage of a competition, sides are reasonably well matched.
"We have got to improve defensively from against Petrarca but if keep on improving we have got a chance."
The European Challenge Cup quarter-finals, to be played on the weekend of 10 / 11 / 12 April, 2009, are:
London Irish (1) v Bourgoin (8)
Northampton Saints (2) v Connacht Rugby (7)
Saracens (3) v Newcastle Falcons (6)
Worcester Warriors (4) v Brive (5)