However, if the relentless progress of Groombridge can't be stalled, then it's likely he'll wrap up the 2018 with a round to spare on Sunday, earning him a third consecutive national cross-country crown.
In the junior grade, Eltham's Adam Loveridge (Husqvarna TE150) has taken charge so far, finishing runner-up at the series opener near Huntly and then backing that up with a solid win at round two near Ormondville.
Raglan's Coby Rooks (Honda CRF250) and Napier's Bryn Codd (Yamaha YZ125) are within striking distance of Loveridge, second equal and just seven points behind.
Meanwhile, Cambridge's Michael Henry (KTM 250 XC-F), Hamilton's Caleb Richardson (KTM 250 SX-F), Dannevirke's Ben Paterson (Yamaha YZ125) and Eltham's Josh Loveridge (Husqvarna FE250) must also fancy their chances, these four riders in a tight battle for fourth overall and separated by just two points.
Racing on Sunday is on farmland at 6204 Western Bay Road, Waihaha, west of Lake Taupo.
The fourth and final round of the New Zealand Cross-country Championships is set for farmland near Mosgiel on May 12.
Only three of the four rounds are counted towards the championships, with riders to discard their one worst score, but there is a stipulation that riders attend the final round, and this means the battle for a coveted podium result could last right until the final lap at Mosgiel.