It was also faster than John Walker’s time when he won gold to win the gold medal at the 1976 Montreal Olympics.
Speaking to the Herald, Ruthe said he was thrilled to finally claim the record.
“I had a plan going into this weekend that if the weather and conditions were good, I was going to go for the record - and fortunately enough it was absolutely beautiful,” Ruthe said.
“I went out a bit faster so I had some room just in case I wasn’t feeling so good, and then I just kept going at that pace and it played out well.”
Ruthe said the achievement was more special because it was done at one of his favourite venues.
“This track became my favourite in New Zealand after I won my first open men’s national title here,” he said. “To come back and break the schoolboy 1500m record just adds another great memory.”
In March, aged 15, the Tauranga Boys’ College student became the youngest person to run a sub-four-minute mile, becoming the 49th New Zealander to break the milestone target in Auckland, in 3min 58.35sec.
In July, Ruthe lowered his own national under-17 and under-18 1500m records with his performance during the Sound Running Sunset Tour in Los Angeles.
The 1500m final is scheduled to run at 2pm on Sunday.
He has also qualified for the 800m final at 9.52am and, depending on conditions, plans to target his own record of 1min 49.59sec.
Ben Francis is an Auckland-based reporter for the New Zealand Herald who covers breaking sports news.