Henry Speight is the hired big gun, but it’s another Henry who is Australia’s new rugby hero after propelling the Thunderbolts into the Sydney Sevens semi-finals.

Teenage speedster Henry Hutchison is the toast of Allianz Stadium after coming off the bench to score two tries and break English hearts in a thrilling 17-12 extra-time triumph on Sunday.

Australia now play world series pace-setters South Africa (4.19pm AEDT) in their first top-four appearance of the season.

Young gun Hutchison, who only joined Australia’s sevens program six months ago, showed extreme pace and strength to tie the scores just before fulltime, and then repeated the dose two minutes into extra time to spark celebrations.

The 18-year-old’s golden try meant the Thunderbolts finally broke their world series quarter-final jinx after being bundled out at the same stage of the previous three tournaments.

“It was awesome,” Hutchison said.

“Coming on with a few minutes to go in the (second) half I was fresh and able to find that extra effort to seal the deal.

“Extra-time is a killer in sevens.

“The boys’ effort was unbelievable. First points win and they were camped out on our 5m line for a minute and a half, and in sevens that’s an eternity.”

Coach Andy Friend admitted he left starting winger Wallabies convert Speight on one minute too long before injecting Hutchison.

“He’s just a finisher,” Friend said.

“He has amazing legs doesn’t he … He’s power and aggression and really, really physical.”

Friend said the victory over world No.4 England was a huge boost to his side’s confidence ahead of their clash with the Blitzboks, who flexed their muscles in drubbing Argentina 26-0.

New Zealand didn’t let a World Rugby investigation into an eight-man breach affect them in their quarter, swatting aside the United States 24-7.

The All Black Sevens face possible disciplinary action from the sport’s governing body with a probe into Saturday night’s pool draw with Australia.

World Rugby says the 17-all result will stand but they are reviewing whether an extra player was on the pitch in the last minute of play, when Ardie Savea scored to tie the match, to “determine if any disciplinary action is warranted”.

NZ took top spot on pool A on for-and-against and played the Americans in their Cup quarter-final, where the Americans put up a strong early fight before failing to capitalise on the first-half sin-binning of Kiwi captain Tim Mikkelson.

New Zealand will play defending champions Fiji in their semi-final after the Fijians disposed of Kenya 28-12.