Valerie Vili won gold in the women's shot put following a dramatic gold to sculling sisters Caroline and Georgina Evers-Swindell.
Vili's best throw was her first which was a national record of 20.56m.
At Shunyi black-singleted rowers clambered on the podium three times, with single sculler Mahe Drysdale and men's pair Nathan Twaddle and George Bridgewater winning bronze before the twins sent the photo finish equipment into a frenzy.
And at the Taoshan Velodrome cyclist Hayden Roulston won silver in the men's 4000m individual pursuit..
New Zealand last won four medals in one day 20 years ago in Seoul, when swimmers Anthony Mosse and Paul Kingsman and rowers Eric Verdonk, Lynley Hannen and Nikki Payne all won bronze.
Today the Olympic treasure trove had a golden glow, as the Evers-Swindell twins overcame 18 months of injury woes, hashed results and even form uncertainty coming to Beijing, to refind the golden smiles that lit up Athens in 2004.
With 500m to row, Germany still had 1.65 seconds on the New Zealanders, but the black singlets descended like an avalanche in the last 100m to grab an unlikely win.
Even the twins could not believe what they had done.
"It's a different feeling (than in Athens)," Caroline Evers-Swindell said.
"This time we were total underdogs, it is a bit of disbelief, actually." Drysdale faded to third, while Twaddle and Bridgewater came home hard for a second, but less dramatic, bronze.
A medical crew was still with a vomiting Drysdale on the water 20 minutes after he crossed the line.
Three-times world champion Drysdale, 29, faded when he had the gold in his sights. He had been hit with a stomach bug early in the week.
"It's an Olympic final, at the end of the day you can only push as hard as you can," he said.
In the women's pair, Juliette Haigh and Nicky Coles were fifth, and Nathan Cohen and Rob Waddell a close fourth in the men's double sculls.
In Qingdao, yachtie Jo Aleh posted her third consecutive second place to take the lead in the Laser Radial class after five races.
Star crew Hamish Pepper and Carl Williams were also poised, sailing to a ninth then a third to sit one point behind fleet leaders the United States after three races.
Unfavourable weather saw boardsailing postponed, while Laser sailor Andrew Murdoch had a 24th and lay 13th overall.
Teenaged 470 sailors Peter Burling and Carl Evans broke through to win an Olympic race, then were seventh, only to miss making the medal race by two points. They finished the regatta 11th.
Track cyclist Alison Shanks qualified fourth-fastest in the women's 3000m individual pursuit, and will ride for the bronze medal tomorrow.
While Vili oozed class, across the Olympic Green at the hockey centre the New Zealand's women's team surrendered any chance of making the semifinals with an insipid 1-4 loss to the United States -- a game they had targeted as winnable.
Needing to win to retain a slim chance of making the semifinals from Pool B, the Black Sticks were 0-1 down after 35 seconds and 0-2 after five minutes.
Meanwhile, heptathlete Rebecca Wardell was also in action on the second and final day of her competition, ending the fifth of seven events in 25th place after a 5.84m leap in the long jump.
With the javelin and 800m remaining, Wardell had 4369 points. Natalia Dobrynska from the Ukraine lead with 5045.
