At round one, Jack (BikesportNZ.com Suzuki RM250) and Mobberley (Spectrum Motorcycles Gas Gas 125) found themselves behind the Yamaha pairing of Chris Power (Yamaha YZ250) and Mitchell Nield (Yamaha YZ125) soon after the start of the gruelling three-hour race.
It was 16-year-old Mobberley's first race back following knee reconstruction surgery nine months ago. So it was a matter of settling into the race rhythm before beginning a push for the lead.
That attack did eventually come from Jack, who took over the lead during his third stint on the track, his two-rider team's fifth lap of six, and the pair maintained that position until the end.
But the winning margin was tight, Jack and Mobberley taking race honours by a little over 30 seconds.
Auckland's James Ainsworth (CRF450) and Daniel Nieuwenhuyzen (Husqvarna 250) held third place until lap four when 14-year-old Auckland rider Jake Wightman, straight from his junior class win at the Dirt Guide Series near Tokoroa the day before, powered his KTM 125EXC past him to snatch third.
His team-mate, James Mancer (Yamaha YZ250), extended the lead and the young team eventually claimed third overall by four minutes.
"It was pretty close in the end," said Jack. "We were being patient and riding smart. We could have pushed sooner and perhaps made the pass for the lead a little earlier, but it was good to make the pass near the end.
"I'm very busy with my work now (as a builder) and don't have a lot of time to train or practise, but I pretty much grew up racing at Woodhill and so it's second nature for me there.
"We will just give it our best shot and see if we can repeat our winning result at round two, but it's not going to be easy."
Reuben Vermeer
Masterton's Reuben Vermeer (Yamaha YZ450F) rode solo for the three hours and finished round one sixth overall, easily winning the ironman section of the race.
Though on his own against the might of two-man teams of elite riders from all around New Zealand, Vermeer was coolness personified.
He headed into battle armed only with raw talent and his trusted 450cc bike, but he emerged at the end of the day with the ironman trophy firmly in his grasp.
Vermeer finished an impressive sixth overall among the 100-plus two-rider entries, proving that both he and his bike were just as fast and reliable as any team over the race's three-hour duration.
The next best solo rider was Taumarunui's Cody Davey (Honda CRF450), who finished the day ninth overall.
The third and final round of the Spectrum Woodhill two-man cross country series is set for Sunday, September 28.