Australia's Chris Burton is in pole position to win the Land Rover Burghley Horse Trials in Lincolnshire after a punishing day of cross-country action.

Burton, the leader following dressage, is a mammoth 11.5 penalties clear of the field on Nobilis 18, meaning he can afford to have two fences down in Sunday's showjumping finale and still triumph.

He would be the first Australian champion at Burghley since Lucinda Fredericks 10 years ago if he prevails and secures a STG63,000 ($A110,000) top prize.

Burton, a member of Australia's bronze medal-winning eventing team at the Rio Olympics, collected just 3.2 cross-country time penalties on a day when not one of 70 starters finished inside the optimum time of 11 minutes 11 seconds.

New Zealanders Tim Price (Ringwood Sky Boy) and Andrew Nicholson (Nereo) lie second and third respectively, with Price's Jonelle holding fourth spot aboard Classic Moet.

Oliver Townend is the leading British rider in 10th spot on Samuel Thomas II, but he retired MHS King Joules on cross-country after lying fifth overnight.