The result came just a day after he shattered the New Zealand Secondary Schools’ 1500m record.
He stopped the clock at 3m 38.62s in the first semi-final of that event, surpassing the previous best time by eight seconds.
That record was set by former Commonwealth Games runner Richard Potts in 1989.
The 1500m final is scheduled to run at 2pm today.
The records add to what has been a big year for the teenage star.
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 3m 58.35s.
Olympian Sam Tanner helped lead Ruthe in the second half of that race, setting the pace for the teenager towards the finish line.
Ruthe finished second behind Tanner in 3m 58.35s, with third-placed Ben Wall also breaking the four-minute mile to become the 50th New Zealander to do so.
In July, Ruthe lowered his own national U17 and U18 1500m records with his performance during the Sound Running Sunset Tour in Los Angeles.