The Hayling Islander and 470 class partner Hannah Mills & Eilidh McIntyre jumped into top spot in Tokyo today with a win and third place in their two races.
Having started the day four points adrift of Polish pair Agnieszka Skrzypulec and Jolanta Ogar in second place, they are now one point ahead of them.
McIntyre, 27, said: ‘We had a good day today, but so did the Polish team.
‘They are sailing amazingly well. It’s really tight on points, it’s really close.
We have to see what tomorrow brings and go out there and get two good results.”
Mills, 33, from Cardiff, is aiming to win her second 470 Olympic gold, having won alongside Saskia Clark in Rio five years ago.
‘Obviously happy with our position but a lot can change,’ said Mills. ‘We have two more races but we are happy with how we have put together the regatta so far.
‘We are trying to be consistent, keep chomping away, get points back. It’s super tight.’
McIntyre was inspired to take up sailing after learning of her dad Mike’s gold-medal winning heroics in the Star class in Seoul in 1988.
Speaking before the Olympics, Eilidh said: ‘One of the really beautiful things about having an Olympic gold medal hanging in the house is that anything seems possible.
‘Why not? My dad did it, so why couldn’t I? That’s been a big aspect of who I am.’