The Blitzboks, competing in their fourth consecutive final of the Series, beat England in what was a repeat of the Cape Town final in December to cement their position at the top of the overall standings.

Their three wins from four is the best Series start for a side since New Zealand in 2008, when the Kiwis won five tournaments in a row.

"It is incredible," said player of the final Seabelo Senatla, will now leave the Blitzboks to join the 15-a-side squad.

"The guys are just magicians, hats off to them, I am just the finisher of the moves.

"It's bittersweet, we play here with family so it is a pity to be leaving the family but it’s a new challenge that I'm excited for."

South Africa imposed themselves early on against England in the final.

Tries from captain Philip Snyman, Senatla and Justin Geduld went unanswered in the first half, while a second from Geduld in the second all but sealed the trophy.

England captain Tom Mitchell crossed for a consolation as did Dan Norton.

However, in between those, Stephan Dieppenaar scored for South Africa to put the game out of reach.

Earlier in the day, England and South Africa reached the final courtesy of 12-5 and 26-12 semi-final wins over New Zealand and Australia respectively.

Australia were then stunned on home soil once again as New Zealand claimed the bronze medal with a 29-14 win over the hosts.

Russia, meanwhile, won the Challenge Trophy in Sydney after beating France 26-0.

The Series now moves to Las Vegas on March 3 and 5 for the fifth round of the tournament, which will again see both men's and women's competitions take place.