Drivers had entered from Rotorua and Kihikihi as well as the local hopefuls, giving it the feel of a national title.
The win for Bayley was set up by a superb drive in the first heat when he came from grid 22 to finish fourth in the 24-strong field.
Bayley followed this up with a third placing in the second heat but he was still five points behind the championship leader Mallia, who had claimed wins in the first two heats. Both were aided by the leaders spinning out of contention - McLeod in the first heat and Maule in the second.
Bayley had the advantage of a grid position at the front of the field in the third heat while Mallia was sitting near the tail.
Bayley was soon in control in the third heat and could do no more but to see how much progress Mallia could make through the field.
By lap five of the 10 laps Mallia had made his way up to ninth and needed to make up three more placings to draw level with Bayley on points.
Trouble struck on the next lap though when Mallia was turned sideways coming out of turn two and left Huntly's Mace nowhere to go and collected the Palmerston North car.
Caleb Churchward, from Hawkes Bay, compounded the situation by ploughing into both the stranded cars.
After the compulsory red light to retrieve the stricken cars, Mallia was able to continue but by then he had dropped too many placings to be able to pressure the Hawkes Bay flyer.
Bayley was able to then complete the final four laps with ease to take the title by a comfortable five points from Auckland's Brown with Joshua Patterson, from Wellington, four points back in third, just in front of the luckless Mallia.
Two Wanganui drivers made it through qualifying to compete in the finals with Shay Bennett-Hintz backing up a strong performance in the preliminary stages to finish 13th overall.
Ben Huijs got caught up in a melee in heat two that limited his chances of a higher placed finish, having to settle for 20th overall.
Given the quality of the field the two drivers would be well pleased to make it through into the finals.
In other races, Bob Smith collected a handful of wins in the superstock/stockcar classes while Craig Scott and Aaron Rose completed a hat-trick of wins in the sidecars.
Stratford drivers dominated the saloons with Nigel Perrett claiming two wins and Ash Cook the other. Daryn Smith collected two wins in the Nathan Smith car in the pro-duction saloons while Hayden Sherman slipped into the seat of the John Caird car to take the feature.
Further afield, Wanganui's Blair Lockett distinguished himself by making the final field of the New Zealand Stockcar Championships at Christchurch's Woodford Glen Speedway.
This was a feat in itself given more than 120 cars tried to make the 30-strong final.
Lockett did not have much luck in the finals and finished 19th overall.
The title was won by reigning champion Peter Rees from Palmerston North.
The New Zealand Superstocks are competed for this weekend at Nelson with Wanganui's Darryl Taylor and Kyle Heibner representing the Wanganui track.
