The 33-year-old's 538th and final competitive match was a fitting finale for the magical full-back and his departure in the 68th minute was met by a standing ovation.
Shrugging off any lingering effects from the dislocated shoulder sustained in England's World Cup final defeat by South Africa, Robinson shredded the Springbok defence with several dazzling runs.
The day may have been all about Robinson, but Twickenham was treated to an entertaining contest that inflicted an anticlimactic end to Jake White's successful reign as Springboks coach.
South Africa looked anything but World Cup winners, lacking inspiration and allowing the star-studded Barbarians line-up to frequently pierce their defence.
They rallied in the second half when the rain restricted the Barbarians' attacking instincts and the attritional battle was far more to the Springboks' liking.
But the damage had already been done with Giteau, Martyn Williams and Rocky Elsom touching down, while Barend Pieterse registered South Africa's only points.
The hero of the first half was Ma'a Nonu, the bulldozing All Black centre who smashed the Springbok defence with a series of wrecking-ball runs.
A number of Barbarians - including Federico Pucciariello, Justin Marshall and Giteau - put their hands up for the man of the match award but Wales openside Williams ultimately took the honour.
Robinson's entrance onto the pitch was emotionally greeted by the reduced 58,000 Twickenham crowd but his first touch saw him swamped by green shirts.
The Barbarians, determined to topple the world champions, won a penalty shortly afterwards and skipper Mark Regan pointed straight for the posts and Matt Giteau made no mistake.
Nonu pounced on a mistake by Ricky Januarie and the ball went through the hands of Giteau, Conrad Smith and Rokocoko before Wallabies star Giteau collected the scoring pass.