British stars William Fox-Pitt and Oliver Townend are still in title contention after a dramatic cross-country day at the Land Rover Burghley Horse Trials in Lincolnshire.
Fox-Pitt and Parklane Hawk - the defending Burghley champions - lie third overnight, with Townend and Armada fourth.
But Captain Mark Phillips' cross-country course was the real winner, with just four of 85 combinations going clear inside the time, including Townend, and a total of 25 retirements and eliminations.
American Sinead Halpin, though, rode the cross-country round of her life to give herself a great chance of becoming the first American rider for 19 years to take Burghley silverware.
Halpin, riding Manoir de Carneville, joined Townend in going inside the optimum time of 11 minutes, 30 seconds, and she has a fence in hand for Sunday's showjumping finale, standing 5.5 penalties clear of New Zealander Andrew Nicholson and Avebury, with Fox-Pitt on 43.4 and 2009 Burghley winner Townend 43.5.
Only 16 of the 55 finishers achieved time penalties in single figures, while high-profile retirements included Townend and Fox-Pitt on their first rides ODT Sonas Rovatio and Seacookie, Mary King (Kings Temptress) and Paul Tapner (Inonothing).
Several other high-profile riders departed the fray, too, the highest-placed being Australian Clayton Fredericks - third after dressage - when Waltersdown Don failed to clear the vast spread at the Cottesmore Leap.
The horse fell back into the ditch, sending Fredericks over the brush fence on his own, but neither was hurt.
Fox-Pitt, meanwhile, said: "It was hard work today.
"The going was quite tacky, although my horse didn't notice the going and he could have gone round again and I shouldn't have got those time penalties, but I did waste a bit of time setting him up for his fences."