The Black Ferns Sevens were first when keeping France scoreless in a 35-0 win, while the All Blacks Sevens shut out South Africa 38-0, the first time in nine years South Africa had been scoreless in games between the two.
The Black Ferns extended their winning streak to 17 games and won their 38th Cup final.
Both teams head their respective points tables. The All Blacks Sevens, with five of 11 tournaments played, are on 85 points. South Africa has 76, Samoa and France have 68, and Fiji and Argentina have 67.
With three tournaments remaining for the Black Ferns Sevens, they are on 78 points, Australia and USA on 66 points, and France on 52.
Jorja Miller was awarded the player of the women's final after a busy game of player assists, including the first try of the game, scored by Tenika Willison. Jazmin Felix-Hotham was put into space and scored her first try with an impressive show of speed.
She was in again seven minutes into the game when France tried to apply defensive pressure only to leave half an opening which she raced through with ease to run away and score.
Into the second half, Miller did more set-up work for Willison to score her second, and replacement Portia Woodman-Wickliffe capped the night with a superb try.
Having gone done to South Africa in their final pool game 14-17 on Saturday, the All Blacks Sevens made their intentions clear from the outset. They harried the Blitzbokke in defence and overpowered their scrum, producing three tries from the set-piece.
Roderick Solo crossed first after sitting his marker on his behind with a clever change of feet, but it was clear the dynamic youngster couldn't last the distance, having injured a leg in the semifinal win.
Joe Webber, named player of the match, scored off the first scrum play, and then skipper Sam Dickson repeated the feat at halftime.
Akuila Rokolisoa had a try ruled out, but from the resulting scrum, he kicked the ball ahead before Blitzbokke halfback Ricardo Duarttee could control it and won the race to ensure the final was safe with three minutes to play.
Amanaki Nicole and Ngarohi McGarvey-Black, who had also had a try ruled out, each scored to round on the win.
It was New Zealand's 62 Cup final win in the series and their third Sydney title after successes in 2016 and 2019.
The two New Zealand sides swamped their opponents to highlight their dominance in both events.
First, the women ran a fancied Ireland team ragged to win 41-0.
Sarah Hirini was outstanding and scored the first try when fending off Emily Lane to race 70 metres.
Then, Lane was in the firing lane when beaten by Tyla Nathan-Wong, who sent a pass wide to Stacey Waaka-Fluhler to double the lead.
Ireland, stuck in their half, as they were for most of the game, tried to kick their way out of trouble, but Fluhler chased hard and won a tackle turnover. Hirini then tidied play five metres out from the line and fired an overhand pass putting Shiray Kaka away on an 80m run to score.
Up 17-0 at halftime, New Zealand opened with Felix-Hotham fed into a gap by Nathan-Wong to outrun the defence. Kaka scored a second from a tap penalty just out from the Ireland line, and then Hirini scored her second.
Replacement Woodman-Wickliffe won a tackle turnover, linked with Kaka, who crossed for her hat-trick.
The New Zealand men followed that by beating France 36-5; the French try ending six games without posting a point against the All Blacks Sevens and scored in the dying seconds.
France had no answer to the power of the New Zealanders, once losing the ball and a try to a counter-rucking ploy and almost yielding another.
Rokolisoa was in outstanding form, scoring a hat-trick of tries, twice outrunning the French defenders on long runs to the line. Leroy Carter scored twice, the first time from more of the assist work of Sione Molia, which was a factor in the first half especially, but the second time from an intelligent break on the blindside from a scrum close to the line.
Solo was forced to leave the field injured, but his replacement Payton Spencer was soon in the action to round out the All Blacks Sevens' scoring.