Ben Ainslie moved back to the top of the standings as British sailors dominated the Finn class on day seven at the World Championships in Perth.
Ainslie won the day's opening race and then finished second as Britons took the top four places in the second race.
Triple Olympic champion Ainslie leads overall from compatriot Giles Scott, with Dutchman Pieter-Jan Postma third.
Briton Ed Wright is fourth and Andrew Mills seventh with two races to come before Sunday's double points finale.
World number one Wright managed second and third places on Friday, while world number two Scott won the second race after a disappointing 10th in the first.
"I had a very bad start," said Scott. "I was kind of on the back foot. I could only pull up to 10th because the spacing was so great."
Ainslie has already been named as Britain's representative in the Finn class for next year's Games but there are still Team GB places up for grabs in three of the 10 Olympic classes.
Although the World Championships is not an Olympic selection trial for the British sailors, those in the men's 470, men's 49er and women's Laser Radial will be keen to impress.
Luke Patience and Stuart Bithell remain the leading Britons in the 470 after ninth and third-place finishes on Friday kept them in second place, behind the impressive Australian pair of Mathew Belcher and Malcolm Page, who won both races.
Fellow Britons Nic Asher and Elliot Willis are fifth overall, with Nick Rogers and Chris grube in sixth.
Bryony Shaw goes into the weekend in fourth place in the RS:X windsurfer class after sixth and 12th-place finishes, while Alison Young is the leading Briton in the Laser Radial in 10th place, with Hannah Snellgrove 14th and Charlotte Dobson 21st.