The German started the day with a seven point lead in the 30 boat 2.4 fleet and duly pressed-home his advantage by winning the first race of the day.

His French rival Damien Seguin finished down in ninth, meaning Kroger needed only 11th place in the finale to guarantee the gold medal.

But, after starting solidly, he collided with Dee Smith of the United States to drift outside his target before a trademark recovery.

He fought back to cross the line in exactly 11th place to win by five points over Seguin as Matt Bugg of Australia took bronze.

“I won the first race so it gave me a bit of a gap to the others," said the gold medal winner.

"Then in the second race I was round about fifth or sixth.

"It was going well and then I had a small crash with Dee Smith from the US.

"It was really not necessary but I did a 720 - it was not close but it makes you nervous for a few minutes, so then I tried to find some free space and I ended up in a position when everything was safe, so I am really happy about that.

“It was a crazy race because at the start it was all so tight and the wind wasn’t good. 

"[Winning] is like the feeling when you win for the first time - ynever get bored by winning a World Championship.”

There was also a nervy finish in the sonar class, where Alphonsus Doerr, Hugh Freund and Brad Kendell hung on by a single point after a third-placed finish in the final race.

John Robertson, Hannah Stodel and Stephen Thomas won the last race to finish on 27 points, just one behind the US winners.

Colin Harrison, Jonathan Harris and Russell Boaden took Australian bronze.

Poland's Monika Gibes and Piotr Cichocki claimed the SKUD18 title after finishing nine points clear of British rivals Alexandra Rickham and Niki Birrell.

Bronze went to Australian defending champions Daniel Fitzgibbon and Liesl Tesch a further 13 points back.