The bubbly, 2.03 metre Cambage, who top scored and led Australia with 17 points, had never dunked in any game before and was almost embarrassed about it afterwards.
"I was just wide open and I felt it so I just did it. I don't know, it was kind of an out of body experience. I wasn't really thinking about it. It was weird," said the 20-year-old.
The dunk put an exclamation point on a 12-0 run by Australia in the third quarter.
Cambage found the lane wide open from near the foul line and made a bee-line for the basket, flushing the ball through the hoop with a one-hand slam that rocked the arena and set off a series of high-fives with her team mates.
"It's good to finally do it and get everybody off my back about it," said the giant Cambage, usually quick to smile and giggle.
"It's never really been in my head all the time. Everyone wants me to do it, but I'm really shy about it. I'm not shy about anything but for some reason when it comes to dunking I'm a bit shy."
The victory changed the landscape of the Group B standings, as triple Olympic silver medallists Australia improved to 2-1 to match Russia by handing them their first defeat.
Unbeaten France have a showdown game against Russia on Sunday.
"It's a very big win, it's a massive win," said Cambage. "It's such a tight pool."
Beyond the result of their key game, the dunk by Cambage could well create a stir among basketball fans and is certain to get plenty of TV exposure and Twitter attention.
"Congratulations to Australia, to coach Carrie Graf and to Cambage who made the dunk," said Russia coach Boris Sokolovskiy.
Russia's American point guard Becky Hammon, who made some big three-pointers to make it close at the end for Russia, also acknowledged the special moment by Cambage.
"It's good for women's basketball. But I didn't like it that I was even in the play," she said, adding with a grin: "I hope I'm not in the picture."
Beyond the dazzling dunk, Cambage hauled down 10 rebounds and blocked two shots. "I tend to think of the key and the inside as my house, so I'm going to look after it," she said.
Pressed further about making such a splash with her dunk, Cambage said: "It's big, like me."
Canada celebrated a doubly satisfying Olympic women's basketball triumph by reaching the quarter-finals with a long-awaited win over rivals Brazil.
The Canadians withstood a fierce third-quarter comeback by Brazil that erased a 14-point halftime lead by solving their full-court pressure to preserve a 79-73 victory and improve their Group B record to 2-2.
Canada, whose best Olympics result was fourth place at the 1984 Los Angeles Games, clinched the last berth from their group to join France, Russia and Australia in the round of eight and leaped for joy on court when the clock ran out.
"It's huge," said 28-year-old forward Kim Smith, who scored 14 points. "It's huge for our program. It's huge for a big group of us who have been around a long time and never beaten Brazil. It's a great feeling."
Shona Thornburn, who turns 30 this month, sank some crucial free throws in the dying minutes to help keep Brazil at bay.
"We've prepared for this, we've dreamed about this and we're getting it together right now," said Thornburn, who contributed 10 points as one of five Canadian players in double figures.
"We believed we could do this. We really believed we deserved to be here. This is the first time we've beat Brazil in like 12 years. I've never beaten them."
Brazil, winners of the last two Americas Championship and twice Olympic medallists, fell to 0-4 after previously losing to France, Russia and Australia.
Erika Souza scored 22 points for Brazil and Clarissa Santos scored 21.
Brazil Coach Luis Tarallo said his team was in transition and that his younger players were worn out from working so hard in their previous games.
"The team was very, very tired through working very hard to win the games," Tarallo said. "They need more experience and training. They are very, very sad."
That, of course, contrasted with the pure joy on the faces of the Canadians, who are ranked 11th and were one of the last teams to qualify for the Olympics.
"We are extremely happy to beat Brazil," said coach Allison McNeill. "They have been a dominant power in the Americas and this is a big win for us."
"In '84 we finished fourth. It's been a long time, so it's pretty exciting to get to the quarter-finals."