Coal Point sailor Will Ryan and crewmate Mat Belcher stayed top of the men's 470 class standings with wins in races three and four of 10 preliminary rounds on Thursday at the Tokyo Games.
Silver medallists at the 2016 Rio Games, Ryan and Belcher led after the opening two races of Wednesday, when second and fifth.
Ryan's sister, Jaime, and her partner Tess Lloyd sit 12th overall midway through the women's 49er FX preliminary rounds.
Also on Thursday, Newcastle swimmer Tristan Hollard improved his time in the semi-finals but fell short of the 200-metre backstroke final.
The 24-year-old was sixth in the first semi-final with a time of 1:56:92, which left him 10th overall after the second qualifier. The eighth fastest and final swimmer into the decider went 1:56:69.
Hollard had also qualified 10th fastest out of the heats on Wednesday, finishing fourth in his race with a time of 1:57.24. The Olympic debutant's personal best is 1:56:40.
Fellow Hunter product Abbey Harkin was just 0.14 of a second short on Wednesday of making semi-finals of the women's 200m breaststroke.
Late on Wednesday, former Norths defender Matt Dawson celebrated his 150th Test cap for Australia in the Kookaburras' 4-2 over New Zealand.
Tim Brand scored twice before setting up Blake Govers' sixth goal of the men's Olympic hockey tournament. Tom Wickham got Australia's other goal, three minutes from full-time.
The unbeaten Kookaburras complete their pool fixtures against Spain on Friday.