New Zealand sailors Peter Burling and Blair Tuke have won gold in the men's 49er class.
The London Silver medallists have dominated the regatta, winning three races and finishing no lower than seventh.
Such is their dominance at the Rio regatta on Guanabara Bay, Burling and Tuke secured gold on Wednesday (NZT) after the 11th of 12 fleet races.
They had built an insurmountable lead by that point and only extended it in the final race of the day to sit 34 points clear of second-placed Germans Erik Heil and Thomas Ploessel.
That advantage is unsurmountable with just the double-points medal race to be sailed on Friday (NZT), involving the top-10 boats.
The gold adds to the silver they won at the 2012 London Games.
They are unbeaten at all major regattas since then and have triumphed at the last four world championships, making them unquestioned world leaders in the class and red-hot favourites coming in to Rio.
The only real hiccup in their campaign came on Tuesday (NZT), when they capsized twice in roaring winds as they were being towed back ashore following the day's racing.