German star Michael Jung served emphatic notice of his Olympic title credentials by delivering an eventing masterclass in Luhmuhlen.
Jung, the reigning world and European champion, took charge of Luhmuhlen's CCI four-star and CIC three-star classes.
And in doing so he underlined the threat London 2012 rivals like Britain's William Fox-Pitt and New Zealander Andrew Nicholson can expect to meet at Greenwich Park next month.
Jung, riding Leopin FST, produced one of only five cross-country clears inside the time from 40 starters around a course designed by Captain Mark Phillips.
It means he will go into tomorrow's showjumping finale on his dressage score of 32.80 penalties knowing that a clear round guarantees him a title won last year by his German team-mate Andreas Dibowski.
Australian Andrew Hoy is Jung's closest challenger after going clear with Rutherglen for an overnight score of 34.80, while British star Oliver Townend is third aboard Armada.
Shropshire-based Townend, the 2009 Badminton and Burghley champion, missed out on selection for Britain's five-rider Olympic team.
But he produced his best display for some time as Armada's cross-country clear replicated Townend's earlier effort on ODT Sonas Rovatio for eighth spot.
Lucinda Fredericks, the leader after dressage, slipped to fourth place on Flying Finish, with Nicholson (Calico Joe) fifth and British rider Charlotte Agnew (Out of Africa Two) sixth.
Twelve combinations were either eliminated or retired, with the retirements including British pair Francis Whittington and Emily Llewellyn.
Jung, meanwhile, can afford to have a showjumping fence down tomorrow with River of Joy and still win the three-star category.Reflecting on his cross-country round with Leopin, Jung said: "I had a little problem at the first water complex when Leopin landed steeply over the boat fence, but apart from that he was really good.
"We are more together as a partnership than we used to be.
"I've been riding him across country in a double bridle, and that has been much better."
British rider Selina Elliott, who is based in the west country, fell from Bodidily early on the cross-country course and was taken to hospital suffering from a broken pelvis.