Younger brother Callaghan Watson, 11, was up against 14-year-olds who had their age and height advantage over him, but still made the podium, winning silver in the senior boys 66kg grade.
The Watson sibling's cousin Kasey Watson, 18, fought in the junior men's weight class of 83kg and the open weight, taking silver and bronze respectively.
As well as the Watson's, Whanganui's Marshall Littlefair, 10, did well in the senior boys 32kg division, winning bronze despite having his nose taped from an injury while competing on the day.
Another newcomer was Adam Frieslaar, 9, fighting in the junior boys 36kg grade, winning gold for the weight class against seven other competitors.
The next domestic competition for the judokas will be the Auckland International Open, being held at ASB Stadium, July 29-30.