As the nation celebrated, Cortnee Vine's winning penalty was already being compared in its impact to the one John Aloisi converted against Uruguay in 2005 to send Australia's men to their first World Cup for more than three decades.
The Matildas have now exceeded anything the Socceroos have managed at a global level and the significance of being one of the best four teams in the world for the first time was not lost on an emotional Gustavsson.
"The amount of heart and soul and passion that this team showed tonight," the Swede told reporters.
"There's different ways of defining success but, for me, success is when you leave it all out there, no matter the result, you play with your heart and give it your best with the crest on your chest and the players did that tonight.
"That represents so much more than 90 minutes of football," he continued.
"The honour it shows to the (former Matildas), all the little kids that this team will inspire in the next generation, and then seeing the nation unite the way it did."
Although Vine will grab the headlines for her winning spot-kick, Gustavsson had a special word for goalkeeper Mackenzie Arnold, who saved three penalties but missed the one that would have given Australia victory before sudden death.
"It was an emotional roller coaster for all of us. It was almost like it was written in the stars when Macca walks up to take the fifth... and then she hits the post," he said.
"For Macca, missing that penalty and then staying in the game and being that player that wins the game for us, it's unheard of. I mean, that mental strength of hers."
Up next for the co-hosts is a semi-final at Stadium Australia in Sydney on Wednesday against European champions England or Colombia.
"I think the number one thing is to embrace this historic night and feel that we are united," Gustavsson said.
"I know that they're going to celebrate this one but from tomorrow they're going to be focused again; they're extremely professional and they're on a mission."
