Britain's all-woman trio of Thomson, Karen Dixon and Ginny Elliot won the team contest, defeating the Australians by 15 points.
Dixon's fifth place on the seven-year-old Get Sharpe gave her sufficient points to overtake New Zealand's Blyth Tait and Mark Todd and so regain the lead in the Land Rover FEI Three-Day Event world rankings.
Hoy, a member of Australia's winning Olympic team in Barcelona, had a worrying journey from England to France.
Initially turned away at the exit port because he was not in possession of a valid visa, he had to travel to London to sort out the paperwork before he could make the trip.
The effort proved worthwhile since his young horse gave him a wonderful ride. He now rates Darian Powers as an Olympic prospect for Atlanta.
Thomson, Dixon and Elliot were equally delighted with their young horses, as was Matt Ryan, the Australian Olympic champion, who finished third on Hinnegar.Reuse content