London 2012 Great Britain team silver medallist Mary King will lead the British challenge at the Pau four-star event in France this weekend.
King and Imperial Cavalier are in sixth place overnight after dressage heading into Saturday's cross-country phase.
Their score of 39.8 penalties was one of six sub-40 dressage scores on a day of high-class action highlighted by the fact that first day leader William Fox-Pitt (Chilli Morning) dropped to 12th.
Australian Christopher Burton is in pole position with Underdiscussion on 34.8, almost two penalties clear of New Zealander Jonathan Paget and Clifton Promise.
Reigning Olympic, world and European champion Michael Jung, though, is lurking ominously in third spot aboard Leopin FST with a score of 38.3.
Fox-Pitt and Bay My Hero are two places behind King, while other British riders further down the leaderboard but still firmly in contention include Laura Collett (Noble Bestman) and Oliver Townend (ODT Sonas Rovatio).
Pau is the first of five events that comprise the 2012-13 FEI HSBC Classics Series, culminating with next September's Land Rover Burghley Horse Trials.
The Series offers a first prize of more than £90,000 and has been won on three occasions during its five-year existence by current world number two Fox-Pitt.