Teenage running star Sam Ruthe continues to mystify the athletics world after running the fastest-ever mile by a New Zealander.

Competing in the Boston University John Thomas Terrier Classic, Ruthe ran 3m 48.88s to smash the New Zealand indoor men’s record, previously set by Nick Willis, while also beating his own Under-20 mile record.

Willis’ time was achieved nearly 10 years ago to the day, when he ran 3m 51.06s in New York.

Ruthe’s time was also faster than Sir John Walker’s outdoor time of 3m 49.08s, which was set in 1982.

Fellow Kiwi Sam Tanner was also competing in the race but failed to finish after feeling tightness in his leg.

Ruthe, from Tauranga, admits he was surprised to run that time having only just landed in the US for a series of races.

“To break the New Zealand record, I am stoked, I can’t believe it,” Ruthe said.

The 16-year-old was the youngest in the race by three years and was competing in a field of professional athletes, including multiple runners who have competed at the Olympics.

Pieter Sisk, who represented Belgium at the 2024 Olympics, came second in 3m 50.31s.

Ruthe moved from second to first over the final lap of the indoor race and his time is the 11th-fastest all-time in the indoor mile.

“My coach, Craig [Kirkwood] wanted me to settle in to about fifth and [Sam] Tanner got me there,” Ruthe said.

“Travel had gone really well and I felt ready. I wanted to race to win and wasn’t wanting a time, but I didn’t expect to run that.

“I feel for Sam, who had to pull out as he felt his leg tighten up. Craig would have had us both under that record if his leg hadn’t gone. Just so grateful.”

The fastest-ever indoor mile record is currently held by Norwegian Jakob Ingebrigtsen (3m 45.14s).

Just last week, Ruthe became the fastest 16-year-old to ever run the mile, achieving the feat at the Cooks Classic when he clocked 3m 53.83s to go under the former world record mark held by Australian Cam Myers.

Ben Francis is an Auckland-based reporter for the New Zealand Herald who covers breaking sports news.