Although none claimed the top step, Oamaru's Joel Meikle and Regan Turner, of Dunedin, were only standing one level lower than their category winners.
Taupo's Cohen Chase won three of his five 250cc races, and finished runner-up in the other two, beating Meikle (16) to the 14-16 years 250cc trophy. Chase was on a roll, having collected the national 15-16 years 125cc class title last season.
''Joel Meikle kept me honest throughout the racing, but it was comfortable for me in the end,'' he said.
Meikle said it was a ''good weekend overall'' and, while he was pleased to win a race and not hurt himself for the first time racing this year, he ''struggled'' with making a few riding errors.
Alexandra's Bryn Gilbert (15) bettered his expectations of a top-five result, placing third on his Honda 250cc motorbike, behind Joel.
Last year he finished in the same position in the 13-16 years 85cc class and was enjoying riding the more powerful machine this season.
Dunedin rider Sam Cuthbertson's high hopes for the weekend in the 250cc class were dashed when he broke his wrist in a second race fall.
In the 8-10 years 85cc category, Regan's father, Deane Turner said he was ''very proud'' of his 10-year-old son, who had a consistent result of five seconds to give him second overall, behind Auckland's Ryan Webley.
Visiting Australian rider Tyler Darby won the 11-12 years 85cc title, with Dunedin's Grason Veitch placing third in this class, accruing four, third places and a second over his five races.
Other class winners were Rangiora's Dylan Walsh who won the 15-16 years 125cc class while Reece Walker, of Nelson, won the 12-14 years 125cc class.
Racing was reduced from seven races per class to five over Saturday and Sunday as wild weather leading up to the event had turned much of the venue - about halfway between Reefton and Greymouth - into a quagmire.
However, fine conditions greeted the riders for much of the weekend and they managed to find traction on the farmland course.
All four top Otago riders will be in action again at the Central Otago motocross championships in Cromwell on May 18.
