Ben Ainslie has set himself the toughest of tests if he is to secure a fourth consecutive Olympic gold medal in what amounts to a "race-off" with his main rival, Denmark's Jonas Hogh-Christensen, tomorrow.
In the conclusion of an epic battle, he lies just two points behind the man who has tormented him all week. The medal decider for the top 10 in the Finn singlehander tomorrow involves a course on the trickiest piece of water, close to the shore and the grassy grandstand at Weymouth.
"Am I where I want to be now? Yeah," said Ainslie, having steadily closed the gap on Hogh-Christensen. "It's going to be a fascinating race on Sunday and I'm really looking forward to it. I know it may sound a bit perverse, but I quite like these situations.
"Jonas has sailed well all week. It's going to be a really tough battle."
If Ainslie beats the Dane by one place in a race that counts for double points that would decide it, unless they had sailed each other to the back of the fleet and the third-placed Jan-Pieter Postma of the Netherlands wins. He would therefore snatch the gold.
The mathematics of Ainslie's situation are easy to work out. A combination of the conditions on the day and the way the race pans out may mean that any game plan the Briton devises will have to change.
Before the Finn shoot-out begins, the Star keelboat will complete its schedule with defending gold medallists Iain Percy and Andrew Simpson carrying an eight-point, four-place advantage over the crew they edged out in China four years ago, Brazil's Robert Scheidt and Bruno Prada.
The Brazilians then have a four-point cushion over Sweden's Freddie Loof and Max Salminen, leaving them with the conundrum of attacking for gold or defending a second silver. The rest are trailing well behind; the medals can only go to these three crews.
In both 470 dinghy classes Britain leads, Luke Patience and Stuart Bithell heading the men's and Hannah Mills and Saskia Clark making an impressive start in the women's.