Last week's B-grade winner Phil Groves dropped his chain early on and despite help from team-mate Steve Cowan who dropped to help pace him back to the peloton they were never able to reconnect with the main bunch.
About halfway through lap one, Bevan Cheatley sent youngster Boaz Darby up the road, then accompanied by clubmates Pat Johnston, Jason Sturzaker, and Adrian Pettit, Wanganui attacked and crossed the gap to Darby with Rainham the only Manawatu rider strong enough to go with them.
The front six worked hard to stay away for the remaining lap and a half.
In a crosswind, the other Wanganui riders sent Darby and Johnstone clear and these two had the finish to themselves. Johnstone a strong second last weekend crossed just ahead of Darby. The latter is still at secondary school and, in only his second season of racing, is showing real promise.
Cheatley and Sturzaker were third and fourth after strong rides, with Manawatu's Rainham fifth, just ahead of Pettit.
Richard Stanton, Rob Gemmell and Lewis Bunker were next home collecting more points for Wanganui and confirming the local team's domination of this grade.
The C-grade race also two laps was a rout for the River City riders with local competitors filling the top eight placings.
Veteran Allan Luff, the Round One winner, was at it again after being allowed to sneak away on lap one with club-mate Paul Forrest, back from a health scare of two weeks ago.
With Wanganui riders policing the bunch behind them, the front two created a big gap and were never hauled back.
Luff crossed one second in front of Forrest for a well-earned victory.
Behind them, Michael Wright and Dan Richards shot clear of the bunch later on lap one after letting Luff and Forrest draw away, then eased up to allow Dave Collins and Ross McNeill to come across to join them.
McNeill dropped away slightly on lap two but the other three worked well and remained well clear of the fragmented main bunch at the line.
Wright, last week's winner, crossed third with Richards fourth and Collins fifth.
McNeill battled on well to come home sixth, with an improved Marty Hewson seventh and Martin Hogan eighth.
In the one lap, 28km D-grade event, local riders Debbie Cain and Jim Callaghan flew the flag for Wanganui with fifth and sixth placings respectively.
Further back Damien Hussey, Craig Whittaker, Jane Winchcombe and Paul Darby filled the eighth through eleventh spots.
Unofficially, Wanganui still holds the series lead but will need to put in a big performance to secure the overall win when the final round is in Wanganui in a fortnight's time.
Results
B Grade: 1. Pat Johnston; 2. Boaz Darby; 3. Bevan Cheatley (all Wanganui).
C Grade: 1. Allan Luff; 2. Paul Forrest; 3. Michael Wright (all Wanganui).