Luke Patience and Stuart Bithell gave Host Nation Great Britain a fine start to the men's 470 regatta as they ended the day top of the fleet, while Denmark's Jonas Hogh-Christensen was one of those who saw his medal challenge under pressure.
Stevie Morrison and Ben Rhodes of Great Britain picked up victories in both of today's races as they re-emphasised their medal claims in the 49er class.
Day 5 saw the leading Sailing contenders push their medal claims, but Australia's Nathan Outteridge and Iain Jensen are among those taking nothing for granted.
Jonas Hogh-Christensen was among those to impress once again as the leading contenders for the Sailing medals continued to make their intentions clear on Day 4.
Finn leader Jonas Hogh-Christensen won the first race in his class of Day 4 at London 2012 as sailors also fought it out in the Star, Laser Radial and 49er competitions.
Irish sailor Annalise Murphy made it a debut to remember at the Olympic Games as she won both races on her first day of competition to take control of the Laser Radial class.
