Iain Percy and Andrew Simpson were Great Britain's only standout performers on a tough second day of sailing for the Olympic hosts.
With Ben Ainslie faltering and none of the other Brits pulling up trees, the reigning Star gold medallists shone as they moved joint top of the overall standings.
Percy and Simpson picked up third and second-place finishes to put them at the top of the fleet alongside Norway's Eivind Melleby and Petter Morland Pedersen.
"There is a long way to go but we did a bit better today on the results card," Simpson said, having picked up an 11th and second on Sunday. "We managed to catch up a bit today, although we had some bad first beats.
"I think we sailed quite well, but we just didn't seem to have a good boat speed at first. We made a bit a change for the last beat of the last race and found a lot more speed, which is great news going forward because we were a bit frustrated.
"That was the good news and downwind we were very fast, which is always a good get-out-of-jail card in these kind of conditions where it is very much a downwind race."
While Simpson and Percy pressed on, Ainslie had a difficult time in the Finn class. The 35-year-old failed to follow up an uncharacteristically good start to the Olympic regatta by ending the second day with sixth and 12th-place finishes.
Ainslie slipped to the bronze medal position behind France's Jonathan Lobert as a result, while Jonas Hogh-Christensen continues to lead the way having yet to finish a race below the Brit.
"It was a tough day. It wasn't very good at all," Ainslie said. "I was pretty frustrated with how I sailed so hopefully I will be better in the coming days.
"Everyone is having ups and downs. Jonas also had a bit of an issue in the second race [when he had to do a penalty turn]. But as far as my own performance goes, I wasn't happy with that at all. I have to improve things for the rest of the week."