She went on to give Kerber a lesson of her life, winning 6-0, 6-2 to seal her place in her first ever Grand Slam quarter-final where she will meet the victor of the match between Sloane Stephens and Anastasia Pavlyuchenkova.
Before arriving in Melbourne, Collins had yet to win a Grand Slam match in five previous main draw appearances, but the stunning upset against the three-time Grand Slam champion was her third win over a seeded player so far this fortnight.
Former US Open victor Sloane Stephens saw her challenge come to a halt in the fourth round too as Anastasia Pavlyuchenkova prevailed in another match to go the distance, and Petra Kvitova demolished 17-year-old Amanda Anisimova.
"I may not have won a Grand Slam match before this week", Collins, 25, said on-court after defeating Kerber, "but I gotta tell you, I think it's gonna keep happening". "There's nothing I could have done..." "I was just trying (but) I couldn't find my rhythm".
"I love making it kind of a war", Collins said.
The 30th seed won the first set but then fell to pieces, eventually succumbing 4-6, 6-1, 6-4.
"I heard someone was yawning during the match though, so I'm sorry".
Ranked 35th in the world, Collins breezed through the opening set in 20 minutes with three service breaks, hitting winners on all sides of the court against the second seed, who had five double faults in the set. "I hope to have many more of these". "I know that I can match it with the best".
She then broke the German once again to seal victory on her first match point in 56 minutes. She believes she deserves to be on this stage and expects to win her matches no matter how deeply into the draw they take place.
Hometown hero Ashleigh Barty also made the last eight after muscling past Sharapova and will next meet Petra Kvitova. It clearly worked out well for me.
17-year-old Amanda Anisimova, after a brilliant victory over Lesya Tsurenko and Arina Sobolenko were defeated by the famous Petra Kvitova. "And being in the quarter-final and in the second week of a Grand Slam, I'm really enjoying it".