William Fox-Pitt could not break New Zealand's dominance as he finished fourth and fifth in the Pau four-star event in France won by Kiwi Andrew Nicholson.
Nicholson leapfrogged his countryman Jonathan Paget to win the £28,000 top prize on his London 2012 horse Nereo.
Nicholson and Paget, both members of New Zealand's Olympic bronze medal-winning team this summer, staved off the challenge of Greenwich gold medal winner Michael Jung, who finished third.
Fox-Pitt, meanwhile, was fourth aboard Bay My Hero and fifth with new ride Chilli Morning, with two other British challengers - Richard Jones and Gemma Tattersall - also securing top-10 finishes.
Paget led overnight after cross-country on Clifton Promise, but one showjumping fence down relegated him to second after Nicholson and Nereo jumped clear.
Pau was the opening competition in the 2012-13 FEI HSBC Classics Series, which carries a £90,000-plus winner's purse and rewards the most successful rider across five major events. It culminates in next September's Land Rover Burghley Horse Trials.
Nicholson was pipped to the 2011-12 title by Fox-Pitt, even though he triumphed at Burghley eight weeks ago.
German star Jung, the only eventer in history to hold simultaneous Olympic, world and European titles, uncharacteristically had one showjumping fence down on Leopin FST, but he still finished just ahead of Fox-Pitt.
The supporting CIC two-star class was won by Australian Christopher Burton on Graf Liberty, with Jung and Fischerrocana FST second and New Zealand's double Olympic champion Mark Todd (Regent Lad) third.
Ruth Edge was the highest-placed British performer, filling seventh spot on Mister MacCondy after eight showjumping faults saw them drop from fourth.