Ainslie's display nudged him 11 points clear of Sweden's Daniel Birgmark in his first outing since December's World Championships in Perth, and a close season in which he underwent back surgery.

Ainslie said: "Considering where I was two months ago, I couldn't be happier to be here and to be racing and be back on the programme, in tune and racing well."

Star duo Iain Percy and Andrew Simpson improved on their overnight position of third to move to the top of their standings, after 12th and third place finishes from today's two races.

Four more British crews are currently in silver medal position, including Nick Thompson, who improved from third to second in his Laser, and Sophie Weguelin and Sophie Ainsworth in the 470 women's event.