Tauranga teenager Sam Ruthe has become the youngest runner to break four minutes for the mile, with a 3m 58.35s performance at Auckland's Mt Smart Stadium on Wednesday night.

Paced throughout by training partner and two-time Olympian Sam Tanner, Ruthe became the first 15-year-old to duck under the mythical benchmark for middle-distance running, despite wet and cold conditions.

Just 24 days short of his 16th birthday, he beat his own previous age best of 4m 01.72s, set at Whanganui in January.

Ruthe subsequently became the youngest man to claim an NZ senior title, when he captured the 3000m crown at Napier, and then added a second, when he deadheated with Tanner over 1500m at Dunedin last week.

Tanner won the race in 3m 58.29s, shouting encouragement to his young rival down the homestraight, while Feilding's Ben Wall also broke four minutes for the first time with 3m 59.00s in third.

The record was previously held by Norway's Jackob Ingebrigtsen, having run 3 minutes 58 points 07 seconds in 2017 when he  was 16 years and 250 days old.

RNZ