As Mark Todd of New Zealand, the gold medallist in 1988, had withdrawn because Welton Greylag was lame from previous exertions in the steeplechase, Great Britain's chances in the team and individual events had so improved that it seemed foolish to take unnecessary risks.
This applied particularly to fiendish structures known respectively as El Corral de la Muntanya and El Raurell, the sixth and 13th of 33 difficulties that stand between the competitors and a clear round.
For Stark there was the important consideration that Murphy Himself, a powerful grey with some of Desert Orchid's aggressive instincts, does not take kindly to a tight rein. 'He pulls your arms out and is inclined to tire himself doing it,' the Scot said. 'It was a job holding him.'
Plenty of people were holding their breath when Stark, ignoring the safer option, chose a line over two hard fences, a small-roofed building, and then jumping clear from a platform.
Similar anxiety was expressed at the 13th, where others had come to spectacular grief as the result of serious miscalculations when springing down from a wide wall into shallow water after scrambling over steep-sided plateaux. There had been enough unseated riders there to suggest a bad day at Aintree. For Murphy Himself it wasn't a problem. 'Wasn't he brilliant at the 13th?' Stark said. 'He jumps so well it's as though you are flying.'
A small error almost cost Stark vital points when he failed to cleanly negotiate the 16th, 17th and 18th, three tightly bunched fences, but he stayed in the saddle to enter today's show-jumping phase in fourth place.
Matthew Ryan, of Australia, leads after a characteristically pugnacious round on Kibah Tic Toc - 'the word was that you needed to go at this course, so I did' - but experts suggest that he lacks the discipline to consolidate his position.
For some, a day at El Montanya was a disappointing experience. Debilitating heat added to the problems, and Richard Walker on Jacana ran out of luck at the 16th, coming off over the horse's head just when it looked as though he would go on to complete an encouraging clear round. 'I chose the right route but didn't handle it correctly,' he said. 'There was a safer way around but to choose the scenic route takes up a lot of time.'
The arrival at the 24th of ambulances for horse and rider signalled more than just a painful mistake. Vasilli Tanas, of the Unified Team, miscalculated so badly there that the obstacle had to be reconstructed, and it was first thought that Darnik would have to be put down.
Confirming the demanding nature of a course that fully tested horses and riders, the equestrian organisation later announced that Darnik was suffering severe exhaustion. It was a wonder that others did not have similar problems but the prize is still within Britain's grasp.
For Murphy Himself it is nearly all over bar the shouting. Asked if he could think of a human to compare with him, Stark said: 'Not one.' He then announced his intention to retire the horse. 'He deserves it,' Stark added. But there is one more day, perhaps a golden day, the best of a considerable career.Reuse content