Caribbean sunshine with a brisk breeze provided perfect conditions for the event, which forms part of Presidente Lay Day.
The challenge commenced with two heats of four teams racing to make the four-boat final.
This year’s teams boasted a star-studded collection of sailors from the Olympics, America’s Cup, Volvo Ocean Race and World Match Racing Tour.
Double Olympian Karl James, featuring in an all-Antiguan team from the Antigua Yacht Club of Shawn Malone, and Bob Green secured race one.
Race two was emphatically won by the Itchenor team, which was made up of Walker, Chris Fox and Richard Bullock.
The three-race final produced an epic battle between Itchenor and Stuart Childerley’s young Antiguan crew, known as Original Drama for the race.
The West Sussex outfit won the two opening encounters, harried all the way by Childerley’s team.
In the final race, Original Drama finally got the better of Itchenor, but Walker’s men came second which was good enough to win the 2016 Nonsuch Bay RS Elite Challenge – and an all-inclusive week’s stay for two at the luxury Nonsuch Bay Resort.
A long-standing member of the Chichester Harbour-based sailing club, double Olympic medallist Walker said: ‘Basically, our parents dumped a load of us in Chichester Harbour when we were still in nappies and we’ve progressed from there!
‘It has been really special to catch up with old friends and to race with them at Antigua Sailing Week.
‘It was a fantastic event and I’d like to thank the sponsors and Antigua Sailing Week for making it all happen.
‘It was superb race management and we hopefully will get to come back next year to defend our title.’
Meanwhile, in further good news for the club, Itchenor has been given the honour of hosting the 2016 Mirror Class National Championships.
The much-anticipated annual event, which will see around 60 boats descend on Chichester Harbour, will be held on August 22-25.
The Mirror Class Nationals is a key date in the sailing calendar and participants can expect to enjoy top-class racing as well as a host of social events.
Commodore of Itchenor Sailing Club, Charles Hyatt, said: ‘We are delighted to host the 2016 Mirror Class National Championships.
‘Itchenor has a very strong heritage in Mirror sailing and the largest racing fleet in the UK, with many of our most successful sailors progressing through junior Mirror racing at ISC.
‘We look forward to welcoming competitors of all ages for high-quality racing and a great social programme.’