In the women's race, Jess Ruthe started off at a very quick pace, going through the halfway mark in 1:22:35, five minutes ahead of the next fastest female runners, but a calf injury with 10km to go ruined her hopes.
Tsuchiya, third in the 2008 Rotorua Marathon, and Erin Furness, winner of the 2013 event took the lead and fought out the final kilometres before the Japanese runner edged ahead and went on to win in 2:53:24, almost two minutes ahead of Furness.
Katie Wyrill from Auckland finished under the three hour barrier for the first time in third place.
Tim Stewart won a very close half marathon in 1:08:28, eight seconds ahead of eighteen-year-old Michael Voss from Rotorua, with Josh Maisey third another six seconds back. All three ran personal best times for the distance.
Lisa Robertson won the women's half marathon in 1:15:34 from fellow Aucklander Alice Mason and Serena Hammond.
More than 5700 runners and walkers took place in the various events over the two days including more1600 children in the mini marathon on Friday.
Results from the Rotorua Marathon on Saturday:
Marathon Men
1. Sam Dobson (Auckland) 2:29:04, 2. Phil Costley (Nelson) 2:29:31, 3. Jonathan Jackson (Auckland) 2:30:26.
Marathon Women
1. Naoko Tsuchiya (Japan) 2:53:24, 2. Erin Furness (Hamilton) 2:55:17, 3. Katie Wyrill (Auckland) 2:58:07.
Half Marathon Men
1. Tim Stewart (Hamilton) 1:08:28, 2. Michael Voss (Rotorua) 1:08:36, 3. Josh Maisey (Auckland) 1:08:42.
Half Marathon Women
1. Lisa Robertson (Auckland) 1:15:34, 2. Alice Mason (Auckland) 1:16:18, 3. Serena Hammond (Thames) 1:22:27.