Sailor Ben Ainslie put a fourth Olympic gold in his own hands heading into Sunday's medal race in the Finn.
The 35-year-old came into London 2012 as overwhelming favourite to top the podium but heads into the final race of the regatta behind Jonas Hogh-Christensen, who has sailed the regatta of his life.
The Dane pulled four points clear of Ainslie on Friday afternoon, but the Briton responded in some style in the final race of the opening series to halve that.
Having got off to a storming start and built up a lead of almost 200 metres, the Macclesfield-born sailor slowed right down in the final upwind leg in a bid to slow down Hogh-Christensen, who was in second.
The Dane struggled with the move rarely seen before a medal race and was overtaken by Holland's Pieter-Jan Postma, who went onto finish second.
Ainslie won the race to put him two points behind Hogh-Christensen in the overall fleet standings heading into the medal race, which is competed between the top 10 boats and sees points scored doubled and added to the opening series' score.
With two points for each position in the medal race, Ainslie will win gold as long as he finishes ahead of Hogh-Christensen and not at the back of the fleet - as that would allow Postma back in should he win the medal race.