New Zealand say they will have "a target on our backs" at this summer's Paris Olympics after beating France 10-7 to retain their Hong Kong sevens crown on Sunday.

Making it a double celebration for New Zealand, their women's team also successfully defended their Hong Kong title with a 36-7 thrashing of the United States.

A cagey men's final, in the most prestigious leg of the World Series, was decided by two quickfire second-half tries by Scott Curry and Cody Vai.

France, winners of the previous leg of the series, in Los Angeles, scored unchallenged at the death through Varian Pasquet, with Rayan Rebbadj nailing the conversion.

But that was the last action and New Zealand's triumphant men and women celebrated at a boisterous 40,000-capacity Hong Kong Stadium by doing the haka.

It was a particularly special occasion for New Zealand's Tone Ng Shiu because he is a quarter Chinese, and also a warning of intent with the Olympics just over three months away.

"Just speechless, unreal, unreal feeling," said Ng Shiu, who is just back from a serious knee injury.

"We know we've got a target on our backs (at the Olympics), but we're trying to take it one tournament at a time.

"We spoke about why we love this game, and at the end of the day, we all came out, prepared well, stuck to the routine and did our job.

"This is a stepping stone, hopefully we can keep rising and peak by the time the Olympics come."

France back Aaron Grandidier acknowledged that the Olympics were on their minds, but said: "It's something that we try and avoid thinking about because there's things we want to achieve before that, there's tournaments before that.

"But it's a home Olympics, it's something that does not even come around once in a generation, so it's difficult not to have in the back of our minds."

No debut title for Hooper

There was to be no first sevens title for former Wallabies skipper Michael Hooper on his debut tournament in the abbreviated form of rugby.

The Australians lost to their neighbours New Zealand 26-7 in the semi-finals.

The 32-year-old Hooper, a veteran of 125 Tests but a sevens rookie, is hoping to force his way into the Australia squad for Paris.

He admitted he has plenty to learn and needs to get fit quick after an Achilles injury delayed his introduction to sevens.

"Just how quick it is, how quick the game is, it's over in a flash," he said.

There was more frustration for Fiji, the reigning two-time Olympic champions, who were defeated by New Zealand in the last eight.

Argentina, who came to Hong Kong as series leaders after five rounds, failed to get out of the pool stage.

They still top the standings but are now just eight points clear of Ireland, who finished third with a 14-5 win over Australia.  

In the women's table, New Zealand — the Olympic champions — are now level on points with rivals Australia at the top.

The next leg of the series is in Singapore on 3-5 May.