New Zealand have remained on course in their defence of the men's and women's World Cup Sevens crowns, with both teams progressing to the final four of their respective draws at Cape Town.
In pouring rain, the All Blacks Sevens needed a second-half runaway try from Moses Leo to complete their 12-5 comeback victory over Argentina in the quarter-finals, after conceding the opening touchdown to the South Americans.
Veteran Scott Curry scored before halftime, converted by Akuila Rokolisoa, to snatch a 7-5 advantage at the break, but Leo sealed the win, when an attempted clearing kick from Sione Molia bounced fortuitously for Leo, who raced from inside his 22 to score.
"As soon as the rain started coming down, the ground got slippery," said captain Scott Curry. "That made it really challenging, but I thought both teams adapted really well, which made for a tight battle.
"As soon as the rain came, we thought, 'It's on'. We'd previewed that, and it's good to get stuff when you do the homework and it comes in the game - that's awesome."
New Zealand will now face Ireland on Sunday night (NZ time) for a spot in the men's final.
Meanwhile, the Kiwi women were more dominant against Ireland, emerging with 28-0 win to advance to the semis.
Niall Williams provided the only try of the first half, but Portia Woodman, Alena Saili and Shiray Kaka all scored from long range after the restart, with Risi Pouri-Lane converting all four.
They will now face France, who pipped Fiji 19-14 with a last-minute try, with archrivals Australia also progressing to the final four.
"We came out with a plan, but credit to Ireland - they put a lot of pressure on our attack," said Williams. "We had to just settle down and take one play at a time."
All Blacks Sevens 12 (Curry & Leo tries; Rokolisoa conversion) Argentina 5 (Schulz try)
Black Ferns Sevens 28 (Williams, Woodman, Saili & Kaka tries; Pouri-Lane 4 conversions) Ireland 0