Powerful New Zealand outplayed error-prone Argentina 38-14 in Cape Town Sunday to win the second leg of the World Rugby Sevens Series.

The convincing victory followed two much closer matches -- a 17-12 quarter-final win over England followed by a 19-12 triumph against hosts and title-holders South Africa.

A new-look New Zealand squad under new coach Clark Laidlaw finished runners-up to South Africa last weekend in the first leg of the 10-tournament series in Dubai.

That result coupled with winning in Cape Town gave the Kiwis an early lead in the overall standings with 41 points, two more than South Africa.

New Zealand began the second leg with an unexpected 22-0 loss to the United States, but bounced back to defeat Spain and Australia convincingly and secure a last-eight place.

"I am so proud of the way the boys fought back after losing to the Americans in our opening match," New Zealand skipper Scott Curry told reporters.

"Today was a fresh start for us in Cape Town and we helped each other throughout the matches. Our team spirit made a huge difference.

"We are now looking forward to the third leg in Sydney during January followed by the fourth in our home town of Hamilton, where the tickets have already been sold out."

After reaching the final with victories over first-day surprise teams the United States and Canada, Argentina made a string of unforced errors against the clinical New Zealanders.

A crooked lineout throw led to the first Kiwi try by giant Joe Ravouvou, who shrugged off a series of attempts to bring him down before scoring.

An Argentine knock-on resulted in a scrum from which another huge Kiwi, Vilimoni Koroi, scored a soft second try

The South Americans reduced the deficit to 14-7 at half-time thanks to a try and conversion from Lautaro Bazan Velez.

Argentina needed to score first in the second half, but fell further behind instead as slack marking allowed Tim Mikkelson to dot the ball down unchallenged.

A second Ravouvou try and one from Regan Ware stretched the New Zealand advantage to 31-7 before Luciano Gonzalez scored a consolation try.

But New Zealand had the final say with Sione Molia racing away to cross the line more than one minute after the full-time hooter sounded.

South Africa failed for the second successive season to win in Cape Town after finishing runners-up to England last year.

They had to settle for third place and bronze medals this time after edging Canada 19-17 in a play-off.

South Africa featured in the most dramatic match of the second day, coming from 16 points behind to pip 2016 Rio Olympic Games sevens champions Fiji 31-26 in the quarter-finals.

"I am going to grow very old very quickly after matches like this," said South Africa coach Neil Powell after a thriller watched by a 50,000 Cape Town Stadium crowd.