Meanwhile the first medals of the 2009 Skandia Sail for Gold Regatta, and the first of the overall ISAF Sailing World Cup titles, were awarded to the winners of the three Paralympic event tonight.
In today's Laser class races, Australia's Tom Slingsby made sure of winning the gold medal at the Skandia Sail for Gold Regatta, while compatriots Nathan Outteridge and Iain Jensen (AUS) wrapped up the 49er class.
Slingsby has impressed throughout the week and his fifth and third place finishes today gave him a 25-point lead over Pavlos Kontides (CYP) that ensured he cannot be caught. Asked if he had raced conservatively today Slingsby said: "It was just the way it worked out. I was trying to win both races again today.
"It's been a tough year and it's good to finally be back at the top. I'm stoked," he added. "I'll do the race properly tomorrow and try not to get in anyone's way who is contending for the podium."
Great Britain will have two sailors in the Medal Race in the shape of Paul Goodison and Thompson, who are fifth and seventh. The British pair completed a one-two by coming first and second in the final race of the day.
Thompson's performance ensured he can't finish any lower than 10th overall in the fleet - which guarantees he wins the overall ISAF World Cup series.
Outteridge and Jensen extended their lead in the 49er class to 33 points with two wins and a fifth place, which means they have made sure of winning the regatta. Emmanuel Dyen and Stéphane Christidis (FRA) lie in second, just ahead of Italian brothers Pietro Sibello and Gianfranco Sibello.
There promises to be some thrilling action in the Men's 470 Medal Race, with the Australian crew of Mathew Belcher and Malcolm Page and the British pair of Nic Asher and Elliot Willis both neck-and-neck on 20 points a-piece. Britain's Luke Patience and Stuart Bithell are in third on 34 points. Spain's Onan Barreiros and Aaron Sarmiento lie just one point behind the Brits in fourth overall. If they can make up one place overall, the reward will not just be a medal, but a podium finish will also give the Spaniards the overall World Cup title.
The Japanese crew of Ai Kondo and Wakako Tabata went to the top of the 470 women's leaderboard for the first time today after winning their first race of the day and they stayed there after finishing fourth in the second.
They are now just one point clear of the Dutch pairing of Lisa Westerhof and Lobke Berkhout, who scored a 3 and 1 today.
"I'm very happy, but there's only point in it," said Kondo.
"We hope we will win it tomorrow," added Tabata.
New Zealanders Jo Aleh and Olivia Powrie, who prospered in the strong winds earlier this week, dropped down to fourth after following their two 13ths yesterday with a 14th and a sixth today.
It was a good day for Britain's Pippa Wilson and Saskia Clark, who came second and fifth to climb from sixth to third. They are nine points behind the leaders, but there are another two crews within four points behind them.
Clark said, "We're still a fresh team and we really feel like we've been making a breakthrough in our communications, particularly in the last two days. That's been reflected in our results.
"We'll just go out there with the aim of sailing for the race win and hopefully that will put us in a good place."
Sari Multala's (FIN) grip tightened on the Laser Radial class, despite the Finn finishing 25th in the last race of the day, which is discarded. Marit Bouwmeester (NED) is second with a fourth and eighth that put her nine points behind Multala with France's Sarah Steyaert one point further back.
The Women's RS:X was the first class in which the 10 for tomorrow's Medal Races was decided. Spain's Blanca Manchon, who has led the fleet from the start, finished second in both races today and will go into the Medal Race with an eight-point lead. Skandia Team GBR's Bryony Shaw was third in both of today's races and remains second overall. Flavia Tartaglini (ITA) scored a 1 and a 4 and goes into the Medal Race in third.
Tartaglini said, "I'm a little bit upset about my last race, but four points is nothing in the medal race. Everything can change in the Medal Race. I've learned that you can easily make up 14 points. You just need to believe."
Brazil's Ricardo Santos continues to lead the men's RS:X class and goes into the Medal Race with an eight-point lead over Portugal's World Cup leader João Rodrigues. Julien Bontemps of France is a further six points behind.
Britain's Iain Percy and Andrew Simpson lead the Star class going into the medal day - they have a 13-point advantage over the Swedes Fredrik Loof and Johan Tillander.
Croatia's Ivan Kljakovic Gaspic goes into the Finn Medal Race at the top of the leaderboard, nine points ahead of Ed Wright of the Skandia Team GBR team, who already has the World Cup title secured.
Tomorrow sees Britain's Lucy Macgregor face Renee Groeneveld of The Netherlands in the best of five final of the match racing. France's double World Champion Claire Leroy and Laser Radial Olympic gold medallist Anna Tunnicliffe of the USA battle for bronze in the petit final.
Earlier in the day the first medals were awarded to the top-three in the three Paralympic events. The USA crew of Scott Whitman and Julia Dorsett won gold in the SKUD18 class, which was also enough to earn them gold in the World Cup series. Britain's Alex Rickham and Niki Birrell took silver in both the regatta and the series.
Rick Doerr, Hugh Freund and Maureen Mckinnon-Tucker, also of the USA, won the Sonar class at the regatta, putting them second in the World Cup series. Britain's John Robertson, Hannah Stodel and Steve Thomas came second in the regatta but took gold ahead of the USA in the overall World Cup series.
And the Paralympic classes finished on a high note for Great Britain as the fourth place achieved by Megan Pascoe in the 2.4mR class was enough to give her gold in the overall World Cup series. Thierry Schmitter (NED) won gold in the regatta from Damien Seguin (FRA), and with André Rademaker (NED) third.
ISAF Sailing World Cup
The ISAF Sailing World Cup 2008-2009 consists of the following events:
16-21 Dec 2008 - Sail Melbourne The Asia Pacific Regatta, Melbourne, Australia
25-31 Jan 2009 - US SAILING's Rolex Miami OCR, Miami, USA
4-10 April 2009 - Trofeo SAR Princess Sofia MAPFRE, Palma, Spain
18-24 April 2009 - Semaine Olympique Francaise, Hyeres, France
27-31 May 2009 - Delta Lloyd Regatta, Medemblik, Netherlands
20-28 June 2009 - Kieler Woche, Kiel, Germany
14-19 Sept 2009 - Skandia Sail for Gold Regatta, Weymouth, Great Britain
Find out more about the ISAF Sailing World Cup, including the World Cup Standings, more on the seven events, the scoring system and the Notice of Series at www.sailing.org/isafsailingworldcup.