Duroy holds a one-point advantage over Andrew Harris on Ballycotton, who has finished 11th and 14th here in the last two years. Just 0.8pt further back come last year's winners, Mary Thomson and King William.
Victoria Latta was disappointed with her test on Chief but pleased with marks which left her a close fourth.
Lynne Bevan, 23, is lying fifth on Horton Point, just ahead of New Zealand's dual Olympic champion, Mark Todd, on Kinvarra. Todd said that the 15- year-old 'likes to do his own thing'. But he seemed happy enough to co-operate yesterday.
Blyth Tait, the Kiwi world champion, is 22nd on Delta despite his belief that the mare's dressage had improved. Tait rides Ricochet in today's second day of dressage which includes Todd, on Just an Ace, and Virginia Leng, on Welton Houdini.
BADMINTON THREE-DAY EVENT (Avon): Standings after first day's dressage: 1 Quart du Placineau (M-C Duroy, Fr) 44.2 pens; 2 Ballycotton (A Harris, GB) 45.2; 3 King William (M Thomson, GB) 46.0; 4 Chief (V Latta, NZ) 46.8; 5 Horton Point (L Bevan, GB) 48.6; 6 Kinvarra (M Todd, NZ) 51.6; 7 Fair Share (C Bowley) 52.2; 8 Stepney Bartholomew (K Dixon, GB) 52.8.Reuse content