The footie legend, 38, left other parents gasping in the 100m sprint watched by delighted wife Victoria and pal Stella McCartney.
Becks got a gold medal which he proudly wore around his neck later while carrying daughter Harper, who’s two next week.
Posh, 39, ran in the mums’ race and smiled as she was beaten by Stella at the school in London.
The Beckhams have moved home from LA after ex-England skipper David hung up his boots in May.
One parent said: “They were like just any other mum and dad. But Becks easily won the race. He beat the other dads by miles. He sprinted to the end in no time at all and left the other less fit dads way behind.”