It was his first visit to the Paraparaumu Beach links on Tuesday and he had the benefit of just one practice round before shooting 69 in his first round yesterday.
While the leaders struggled in the increased wind and tricky greens, Groom held his composure after bogeying the first hole to shoot three birdies and the comfortable eagle on the last.
He hit a straight drive off the shortened 18th tee then landed a five-iron within four feet before holing the putt.
The eagle tied him for the lead with New Zealand’s Steven Alker, before Alker blotted his copybook with a bogey on the par-three 15th to drop to five-under. He recovered with a birdie on the last to tie with Groom after second round 70.
Alker earlier eagled the 500m par-five 12th to take over from overnight leader Scott Gardiner who dropped back.
After a birdie on the 18th having taken a free drop out of the grandstand, Gardiner bogeyed the first and second holes to drift to four-under then bogeyed the sixth.
Australian trio James McLean, Brett Rumford and Craig Spence all remained in contention at five-under late in their rounds, with Rumford a model of consistency at even par for the day.
New Zealand No 1 Michael Campbell, seeking to reclaim the title he won here two years ago, eagled the 12th in just his third hole of the day but remained at three-under to stay in touch.
World No 1 Tiger Woods was about to tee off in fine but windier conditions than yesterday when he shot a one-under first round of 70.
