Defending champion Fiji and archrival New Zealand came back in dramatic style to win their opening pool matches in Hong Kong Sevens rugby on Friday.

Fiji rallied from 17-5 down with two minutes to go to pip Canada 19-17, while New Zealand overcame a 17-0 deficit to beat France 19-17.

South Africa's bid to win Hong Kong for the first time was set back when it lost to four-time champion England 21-14 in the last match of the day, with the field worryingly cut up with still two days to go. Also, Australia railroaded Argentina 28-0, and Kenya ran over Samoa 24-0.

Fiji, the world series leader by one point over South Africa and two over New Zealand, scored first against Canada through Savenaca Rawaca, but after Fiji's Masivesi Dakuwaqa was yellow-carded for an illegal push, Canada immediately hit back with tries for John Moonlight and Sean White.

Moonlight's second to start the new half pushed Canada 12 points ahead. The Canadians looked like holding on at 17-12 until Justin Douglas and Harry Jones were yellow-carded in the last two minutes and, with seconds to go, Semi Kunatani exposed the outmanned defense to score between the posts, giving Osea Kolinisau the comfortable match-winning conversion.

France crossed three times through Julien Candelon, Six Nations star Viri Vakatawa, and Jonathan Laugel before New Zealand woke up and hit back with a relieving try to Tim Mikkelson before halftime, followed afterward by scores to Kurt Baker and Mikkelson's match-winner.

England hasn't impressed in the last three legs but answered its large expatriate support in Hong Kong with a rousing win over South Africa. Dan Norton caught a lucky bounce from the restart for his first try and 14-0, then caught his own up-and-under before being held back on the line and earning a penalty try for 21-7. South Africa could puncture the defense only once more, and lost a last-chance lineout throw-in.

"The boys were pumped for tonight, there is no place like Hong Kong for us," England's James Rodwell said.

The United States, Wales, and Scotland were also first-day winners.

-AP