She used a 6-iron to achieve golf's ultimate shot but didn't actually see the ball go in.
The shadow of a large tree on the right side of the 118-metre sixth dimmed her view although playing partner Vicki Fraser suspected the ball was in the hole.
Another player in their group, Colleen Skuse, raced up the green in her buggy, ran over to the flag and confirmed it.
The reaction?
“Excitement,” Rosie said. “It was almost a numbing feeling . . . it was so easy.”
She was, however, quick to point out “that doesn't mean I'm a good golfer . . . I'm pretty average”.
Rosie started golf at Tahunga “some time ago” and played on and off for several years before “cranking it back up again”.
Learning at Tahunga proved quite a challenge but she enjoyed it and she loves playing at the Bay.
“It's such a lovely course . . . once you have been away it makes you realise how fabulous it is.”
She doesn't recall going close to an ace in the past.
“To be honest I've had very few twos (let alone a one).”
Rosie is known for giving the ball a good smack off the tee although direction can be a problem.
For example, she recently carved her drive off the 18th tee and her ball hit a truck heading along Awapuni Road.
She had no idea if the driver knew.
“I scuttled away.”
With no bar open, Rosie did not get to “celebrate” her ace on the 19th.
But social media meant news of the feat was quickly circulated.
“I got lots of lovely messages from all sorts of people.”