Since then, the two Taupo terrors have stepped it up a notch.
Cohen and Wyatt each dominated their respective bike classes at the Wellington Motocross Championships near Foxton a fortnight ago, an ideal warm-up for them before heading across Cook Strait to tackle the South Island's premier stand-alone motocross at the weekend, the 30th annual Michael Godfrey Memorial Motocross, just north of Christchurch.
"It was a home-coming of sorts for us," said the boys' father, Steve.
"They were both born in the South Island, at Takaka [near Motueka]."
It was a sensational trip south with both brothers again dominating their respective classes at the Michael Godfrey event.
Cohen finished 1-2-1-1-1 in his five races in the 14-16 years' 250cc class, while Wyatt produced an identical score-line in his 12-16 years 85cc/150cc division.
"It was good to send a message like that to the junior motocross community," said Steve Chase.
Although he has been riding the 250cc KTM for only two weeks, Cohen Chase also won the junior 125/250cc feature race, finishing a long way ahead of leading national riders Dylan Walsh and Cody Murphy from Christchurch.
Wyatt was also triumphant in his Junior 85cc feature race, winning ahead of Clayton Roeske and James Scott.
"Wyatt has only been back on his bike for a year.
"He broke his femur and was out for an entire season, but already he's back on the pace ... even faster and stronger than before."
The next major assignment for the Chase brothers is to race the New Zealand TT Championships near Kuratau on July 20-21.