Sam Griffiths and Real Dancer.
Burton's second mount, Holstein Park Leilani, is 15th with 50.6. and Griffiths has Paulank Brockagh in 19th with 54.2.
Griffiths said it was "really cool to see so many Australian riders at the top of this World Cup Class."
• France's Sophie Caron riding Lartiste de Courthoe won the CIC* Grand Prix Conseil Général de l'Orne from 113 other starters, in her first international win. The 27-year-old riding instructor beat another French rider, 1993 European Champion Jean-Lou Bigot, riding Qeunji de Beny. Britain's Jodie McGregor on the appaloosa Spot On XII was third.
Mark Todd and Alfiano del Ferro finished 36th.
• In the CIC** Grand Prix Région Basse Normandie Belgian rider Lara de Liedekerke and Ucello vd Zuuthoeve have the lead with 41.7, ahead of Mark Todd and Willy Do with 45.0, and Switzerland's Felix Vogg on Maverick McNamara third with 47.3. Vogg is also sixth on his second mount Onfire, just behind Kenki Sato (JPN) and Karim Laghouag (FRA), equal 4th.