"It could be all the sweeter if we could turn over the world champions and then go into the 6 Nations and beat the (World Cup) runners-up," said Hook, who will win his 20th Wales cap at the weekend.
"That would transform Welsh rugby overnight.
"At the World Cup, we didn't get the chance to play against South Africa - so this is a great opportunity to try and change things around."
Wales were due to meet the Springboks head on in the quarter-final in Marseilles, but their shock defeat against Fiji saw them crash out of the competition at the pool stage.
"It was a hugely disappointing World Cup. But we've got to forget about that, put that behind us and start afresh," said the Ospreys number 10.
"We want to put as good a performance in as possible for the fans as well - because obviously they were disappointed after the World Cup.
"It is no good looking back to the World Cup. We have to learn from our mistakes and look to go forward.
"It was obviously disappointing that we didn't play South Africa in the World Cup - but if we can beat them things will turn around quite quickly. What has been done in the past has been done."
Hook is sure Wales have the team - their 22 contains another eight Ospreys - to overcome an under-strength Springboks for only the second time in their history.
He believes victory is all important but insists Wales cannot ditch the attacking brand of rugby which has served them well in the past and brought them the 6 Nations Championship Grand Slam just two seasons ago.
"We have got to have a sort of cup rugby mentality, play in the right areas and take the points on offer," he said.
"But naturally we have got flair, and it would be stupid to take that away from us. I think we have got the talent to match South Africa up front and behind. We have also got a great back-line, I am sure of that.
"If we can get a good platform up front, we have got some fantastic runners. We want to put up a good performance, not only for ourselves but for the fans."
Part of the attraction of Saturday's match, being played for the Prince William Cup, is the pairing of Hook and Gavin Henson at fly-half and inside centre respectively for only the second time in an international following the 29-29 draw with Australia a year ago.
Henson's career has suffered major injury setbacks since the failed British Lions tour of New Zealand two years ago - and he was left out of Wales' World Cup squad.
"Gavin is coming back to his best, and I really enjoy playing alongside him,'' insisted Hook.
"He brings the best out of me, and I think I bring the best out of him.
"We understand the way each other plays. It is nice to be involved with him for the Ospreys and for Wales."