"In two days, it's my birthday so it's the best gift I could give myself," commented the player who will turn 32 on Saturday.
That day, she will face the Slovenian Tamara Zidansek (29th) or the Briton Heather Watson (94th) for a place in the round of 16.
But she didn't know it yet when she left the Rod Laver Arena victorious on Thursday.
"I don't know who I'm playing against because when I saw the table with Garbine in the 2nd round, I said to myself + let's wait and see ... +", she confided.
The Spaniard made too many mistakes (33 against 16 for the French) to worry Cornet who was perfectly in her game.
"My state of mind was perfect. I was super focused, I felt like I was in a bubble. I'm very happy," she said.
The Frenchwoman did not have a single break point to save, while Muguruza was under pressure on almost each of her service games, with a total of 14 break points conceded in the game, 9 of which were saved.
In the first set, Cornet thus obtained at least one break point on each service game of his opponent.
Of the 10 in total, she converted one.
In the second set, the French converted the two break points played, concluding the game on the first of three match points in a row obtained on the Spaniard's serve.
Cornet remained on three consecutive eliminations in the 2nd round in Melbourne where she had reached the round of 16 in 2009.
The Frenchwoman is taking part in her 60th consecutive Grand Slam tournament.
She has never reached the quarters yet.
© 2022 AFP