Sir Mark Todd is leading the Burghley Horse Trials as he endeavours to win his sixth title, 18 years since his last.

The decorated Kiwi eventer and his mount Leonidas II have returned the best score of 36.7 penalties in the dressage.

Todd said he's chuffed.

"I mean I joked with somebody beforehand, they said 'how's he going', and I said it brought tears to my eyes and it very nearly did."

Andrew Nicholson and Nereo are currently fourth.