New Zealand came from 21-7 down to beat South Africa 24-21 in the Wellington Sevens final on Sunday, the third round of the World Rugby Sevens Series.

Sonny Bill Williams had already earnt currency in his debut Wellington Sevens Championship, the two-time rugby World Cup winner helping New Zealand to a 25-5 win over England in the semi-final.

But now it was time to turn his attentions to the final. A showdown with South Africa.

It didn't start well for New Zealand, going 14-0 down inside the first nine minutes. Rosco Speckman with South Africa's second early try.

Just before the break, New Zealand asserted, one of the biggest on the pitch Akira Ioane powering through with this try. At the break South Africa led 14-7.

In the second half Williams was reminded why he's the new boy to sevens - this loose pass gifting a try for Seabelo Senatla in the 12th minute.

But brilliantly New Zealand got themselves right back into the game. There were two tries from Rieko Ioane before Tevan Webber completed the comeback, coming off the bench in the 22nd minute to score the winner

The 24-21 victory giving New Zealand a hat-trick of titles in Wellington.

The side move from seventh to third in the World Rugby Sevens Series standings. Despite the defeat, South Africa move top.