The second run was a dramatic affair. Goacher and Harper, who raced an unnamed boat, turned the spreader mark right on the stern of the Jerwoods boat Ineffable when both crews were around 20th place in the 57-boat fleet.
A collision from a luffing incident on the downwind leg ended up with a red flag on each of the lead boats, along with a small hole in Ineffable.
Although the Aussies crossed the finish line in fourth place and Goacher and Harper in 21st the Brits had the final say in the protest room, where the Jerwoods were disqualified from the final race.
Goacher, who was competing at this 12th worlds, had also previously won in Cowes in 1997 and Western Australia in 1999. For Harper it was his first world title.
"I've been unlucky a couple of times so it was good to get my first. Steve's four titles is a record too," Harper said.
"I think we will be allowed one glass of wine tonight because we have to fly out in the morning," Harper joked.
"Definitely a quiet night for us," Goacher said.
Boatbuilder Harper and sailmaker Goacher have only been racing together for the past two years. But both have been involved in the sport for years with Harper taking up the sport as a four-year-old and Goacher also as a youngster.
There's a strong chance they will attempt to go back-to-back when Ireland hosts the next worlds in 2019.
"I hope Tim will still have me," Goacher quipped as the banter continued between the jubilant poms.
Goacher claimed it was one of the tougher championships he had raced in more than 25 years in the class.
Harper hails from Southport, between Liverpool and Preston and Goacher from Windermere Lake which is renowned for windy racing conditions.
They finished six points ahead of the South Perth Yacht Club's Jerwoods on the final standings and Aucklanders Murray Gilbert and Jonathan Burgess, who raced Ffrantic, were the best of the Kiwis in third place 12 points behind Goacher and Harper courtesy of their fifth placing yesterday.
Skipper Hayden Percy and Scott Pedersen, who raced Fflorin were the best of the Napier Sailing Club contingent with sixth place, 16 points behind the winners.
Percy and Pedersen also had the honour of being the first Silver boat.
Great Britain's Nicholas Heath and Philippa Noon, who raced Fighting Fit, captured the silverware for the first Classic division boat.
Canberra Sailing Club general manager Matthew Owen and his clubmate Andrew Reed had the opportunity to complete a world championship-national championship double after winning the national title eight days ago but with a 13th placing yesterday achieved their goal of a top five finish, 15 points behind the winners.
With Owen's Napier-born wife Karen celebrating her 50th birthday this weekend this pair will have plenty to celebrate.
Yesterday's race was delayed for an hour as the NE/E breeze kept shifting from side to side causing two general recalls.
On the third attempt the race began with a 1.1nm beat into a sloppy chop.
Gilbert and Burgess and Percy and Pedersen were dominant during the early stages. Great Britain's Jeremy Davy and Martin Huett, won the race to take their first gun of the regatta.
Fellow Brits Greg Wells and Richard Rigg were second and Aussies David Yu and Chris Nelson from the Royal Freshwater Bay Yacht Club in Perth were third.
Davy and Huett were seventh and Wells and Rigg eighth on the final leaderboard.
With their disqualification the Jerwoods hopes of repeating their 2005 world championship victory in Auckland were dashed.
The Great Britain pair of Charles Apthorp and Alan Green, who finished second in 2005, finished fourth overall this week.
Expect the Hawke's Bay Airport to be busy this morning as international crews fly home to catch up on chores after a fortnight in Napier.
The majority should be taking pleasant memories after a regatta well run by Napier club commodore Paul Redman, regatta convenor Graeme Robinson and their huge group of volunteers.