A junior runner produced an “insanely good” comeback in a 4x100m relay event when he took the baton for the final leg in seventh place and powered past his rivals to win.

Sebastian Spencer clocked in at 43.89 seconds at the West Virginia State Championships on May 19 — despite languishing well behind the front of the pack when he joined the race.

It was the highlight of a hugely successful day for Spencer who won each of his four races.

Footage from the televised event shows Spencer, of Weirton, West Virginia, blazing past each of his rivals, before crossing the finishing line just ahead of the second-place runner.

As a replay of the race plays, stunned commentators remark that Spencer’s achievement is “insanely good” and “unreal.”

Spencer, who was representing Weir High School where he is in the 11th grade, claimed gold with a time of 10.60 seconds in the 100m — breaking the record previously set by his older brother, Donavan in 2017.

Spencer was the last runner in the 4×200m — and despite taking the baton in third place he won with a time of one minute and 30.43 seconds.

He also won the 200m, with a joint record time of 21.61seconds.

Commenting on his successful day, Spencer told the Weirton Daily Times: “These are my teammates, but they’re really my brothers.

“To be able to win these relays, get these gold medals and to see all my teammates on the podium with the gold medals is amazing.”

Spencer is a multi-talented sportsman who also plays for Weir High School’s, Red Riders American football team. (SD-Agencies)