An under-strength Australia have unfurled their best performance of the sevens world series season, beating Argentina 21-5 to win the Plate final in Wellington.

The Thunderbolts gave themselves a boost in confidence heading into next week’s inaugural Sydney Sevens by finishing fifth, having won five of their six games.

Unbeaten in pool play, they lost their quarter-final 26-14 to South Africa on Sunday, mirroring their losses at the same stage of the first two tournaments, in Dubai and Cape Town.

However, this time they went on to claim the second-tier prize, beating the highly-rated United States 17-5 before the three tries-to-one defeat of Argentina.

It lifts Australia from eighth to seventh after three of 10 rounds, with the young side applying selectorial pressure after a number of key players weren’t selected this week.

Regular captain Ed Jenkins and key attacker Cam Clark were rested to prepare for Sydney, where Wallabies playmaker Quade Cooper is also expected to make his sevens debut.

They fielded an interim captain in evergreen half James Stannard and an interim coach in Scott Bowen.

New head coach Andy Friend watched from the Westpac Stadium stands but will take charge in Sydney.

Stannard, 32, delivered a reminder of his class with neat touches throughout his 26th tournament.

He also reached a milestone by lifting his points tally in all world series tournament to 638 – seven more than previous Australian record holder, Peter Miller.

Stannard brushed the record to one side after eclipsing it against the USA.

“It’s not about that really, it’s about how we perform as a team,” he said.

“We’ve improved in each step but against a quality team like South Africa, make a couple of mistakes and they’ll put you to the sword.”

A standout performer was speedster Greg Jeloudev, who scored five tries, but a number of rookies also impressed, including Henry Hutchison, Stephan Van Der Walt and John Porch in his tournament debut.