"I will be surprised if we don't walk away as winners," Botha told BBC Wales.
"Unfortunately for the Lions, South Africa are in good shape at the moment.
"The outstanding players of the Super 14 have been our players and that is a good omen for us.
"We are playing a faster game at the moment and the guys physically are in unbelievable condition."
Although the man who kicked the Boks to victory over the 1980 Lions believes the tourists have plenty of talented players themselves, he expects the hunger of the Springboks to avenge their 1997 defeat to the Lions to make them unstoppable in June and July.
Botha made special mention of two Welshmen and an Irishman who he feels will impress on the hard grounds of South Africa but the 51-year-old still anticipates that particular trio returning home empty handed.
"Shane Williams is playing in a different class. If you feed him the right amount of good, clean ball on the outside he is going to score tries," said the ex-Northern Transvaal and Rovigo fly-half who made 28 appearances for South Africa between 1980 and 1992.
"Brian O'Driscoll is a fantastic captain. The way he played this whole Six Nations he should have played himself straight into the captaincy.
"Mike Phillips I think by far is the (Lions') better scrum-half. Physically he is such a strong player. He has got a fantastic pass and his kicking game is not that bad. His cover defence is good as well.
"(Many) players don't get that Lions tour on the CV. That's why I believe the (South African) players know that and that's why they are hanging around. They want to make it a big one."