Simon, who was born in Germany and has been riding for Austria since 1972, defeated Germany's Olympic champion, Ludger Beerbaum, on It's Me. William Funnell was the best placed British rider when finishing third on Comex.
Simon has declined invitations to jump at Olympia during the last ten years because he did not feel that he had the right horsepower.
"When I have very good horses, I decide to come back," he said, having been given a firm invitation to compete here only last Sunday.
He now has a formidable string, among them Cash with whom he won the earlier Christmas Candle Stakes. This eight-year-old homebred horse is out of his former show jumping mare, Landgrafin. His best horse, ET, is resting at home in preparation for Atlanta next year, when Simon expects to compete in his seventh Olympic Games.
Earlier, Michael Whitaker gave one of his inimitable performances with 17-year-old Everest My Mesieur yesterday, when he won the Father Christmas Stakes during the opening session. The French-bred horse, who is exceptionally fast and careful, has now won around 80 international classes.
Whitaker confirmed that he has to do little more than point My Mesieur in the right direction when riding him in speed competitions, which are the horse's special forte.
Yesterday he took the shortest possible route to beat a wonderful round from James Fisher on Monterrey (another speed specialist) by 0.58sec. "I reckon he's won about 80 classes and my problem is going to be finding another one like him," Whitaker said.
OLYMPIA SHOW JUMPING CHAMPIONSHIPS: Christmas Candle Stakes: 1 Cash (H Simon, Aut) clear, 48.26sec; 2 Everest Magic Carpet (M Whitaker, GB) clear, 50.09; 3 Everest Sublime (N Skelton, GB) clear, 51.32. Father Christmas Stakes: 1 Everest My Mesieur (M Whitaker, GB) 37.94; 2 Monterrey II (J Fisher, GB) 38.52; 3 Elegast (C Martinez de Irujo, Sp) 39.62. Christmas Turkey Stakes: 1 Apricot D (H Simon, Aut) clear, 29.57; 2 Sprehe It's Me (L Beerbaum, Ger) 31.25; 3 Comex (W Funnell, GB) clear, 33.77.