Johnston then had a running battle with Nathan Black in the feature race, and their struggle left them several laps down when Chet Swan won in his 9V car.
Black would also win the best stirrer prize in the PAUA Print Grand Slam, which was won by Brendon Learmonth in his 174V car despite having a heavy collision with the wall earlier in the day.
The Remax Realty Youth Ministocks had the biggest fields of the day, with visitors Dion Henderson (45K) and Jackson Evans (47H) taking two races each.
Bradley Korff (86S) took a clean sweep of the River City Press Adult Ministock races, while Ryan Nolly (72S) got two second placings and one third.
The Caird Bobcats Production Saloons also had a good field and Hawkes Bay visitor Brendon Zachan won the first race and the feature.
It was the first event under the leadership of new club president Daryl James, who replaces Alan Luoni.
Numbers were up for the second meeting last Sunday, covered by Stuart and Aimee Barnes.
Mooney shook off his previous mechanical issues to make a clean sweep with four wins, including the PAUA Print Grand Slam.
However, there could be some competition as Scott "Scooter" McIntosh, contracted to Oceanview this season, took an early lead in Race 1.
Mooney spun Johnston out on the way to getting the chequered flag, followed by McIntosh and Francis Potaka.
Johnston, McIntosh and Potaka gave Mooney a battle through the day.
In the Sharp As Superstocks, Scott Duncan got the win in Race 1 when Ron Tye's 599v car had mechanical issues, and would back that up with two more wins when Tye did not return.
Remax Realty Youth Ministocks saw wins to Karl Rowe (43P), Trazarn Ryland-Annabel and, for the first time, Brody Casey.
Ayrton Smith (64P) and Bradley Korff (86 S) shared the spoils in the River City Press Adult Ministocks.
The Production Saloons' first race saw Steven Davis (17V) lead from start to finish, while the feature race was a great battle between Davis, Grant Little (5V), John Huijs (74V) and Jason Pointon (71V) - with the Little car taking the win.
In the Minisprints, Shane Dewar's new 41P machine was the class act of the day, powering to a clean sweep of victories after Cameron Hurley (82V) lost power while leading the opening race.
Tomorrow at Oceanview, the racing begins at 3pm for a programme features Superstocks, Stockcars, Youth and Adult Ministocks, Sidecars and Production Saloons.
After a short break, the next event will be the big annual fireworks meeting on November 26, which will feature the Trev's Concrete Stockcar Shootout and the West Coast Youth Ministocks.
The representative team of the Wanganui Vulcans will be competing at the the Huntly Teams Invitational on November 18-19.