It is the first time the women's sevens has featured at the Games, writing New Zealand into the history books claiming both titles in 2018.
The women's Final played first, New Zealand going out to a 12-0 halftime lead before Australia clawed back in the second half to take the match to extra time.
But England made it a thrilling finish, narrowing the gap to just five points with 25 seconds to go.
Then it was the turn of New Zealand and Canada, the second and third ranked teams in this year's HSBC World Rugby Women's Sevens Series, to duel for top spot in Pool A and a semi-final with the Pool B runner-up on Sunday.
Captain Sarah Goss opened the scoring for the Black Ferns with a well taken outside break.
"They held their composure, like we did", Walsh said.
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Ramirez added an RBI double and scored on shortstop Manny Machando's throwing error - his second of the game. Marcus Walden gave up one run on three hits over three innings, good enough for his first big-league save.
Tonegato scored a stunning hat trick to put her side in the gold medal match and that was the best sign yet that the Aussies are on song ahead of their showdown with New Zealand.
A Fijian player was then sinbinned for a unsafe tackle with a minute left in the first half and New Zealand should have made the most of it, but Regan Ware dropped the ball over the tryline, blowing what should have been a guaranteed try on the stroke of half-time.
Regan Ware matched that with a couple of sidesteps of his own to beat four defenders on his way to New Zealand's second try after four minutes.
Having not dropped a single quarter all tournament, the Diamonds faltered at the final hurdle in the face of relentless pressure from the Roses in front of a stunned crowd at Coomera. The New Zealand men celebrated later with a bare-chested haka on the field.
"We watched the women go into overtime and their win at the end really inspired us to get the double", said Tim Mikkelson, who was also part of the New Zealand squad that won gold in New Delhi in 2010.
Both teams set up semi-finals against England, played earlier today, with the women winning 26-5 and the men 17-12, setting up Finals against Olympic champions Australia and Fiji.