"Geordie has risen to national prominence in the past fortnight, but he has also caught the eye of international judges for some time now," McNab said yesterday.
"He is showing as much talent as his brother Hugo, who coincidently finished a fine fourth in the men's 5000m at a big international meeting in Melbourne on the same night."
At the New Zealand Championships a fortnight ago the younger Beamish set a huge personal best over 3000m in the men's U18 grade, losing out to Priddey.
On Saturday, Beamish marginally improved his best, but more importantly reversed the result of Priddey to win by a few metres in 8:37.16.
Beamish who had won the 2000m steeplechase in Auckland, sidestepped that event in Masterton to challenge himself to break 4 minutes over the classic 1500m.
He rose to that challenge by taking 8sec off his best with a time of 3:59.08.
His blistering finish only just failed to reel in Priddey who had boldly raced to the front. Priddey's winning margin was just .04sec.
"And William is really starting to make his mark, winning the 100m on Saturday in a slick time of 10.99sec, which was just one-hundredth of a second shy of Daniel Natusch's Collegiate record," McNab said.
"A year ago at the nationals, people were asking 'who is this guy?' Now they know. William has great potential.
"Hopefully he makes the New Zealand team to Oceania in early June and meets good opposition and favourable conditions.
"Unfortunately, a hamstring strain clearly affected the New Zealand men's U20 200m champion in his strongest event (on Saturday) where he finished back in fifth."