There was foreshadowing - not only had Cibulkova beaten Sharapova at a Grand Slam before, but she also looked fantastic in the previous round, crushing No.16 seed Carla Suárez Navarro, 61 60.
The No.3-seeded Sharapova looked sharp in the first set, keeping her numbers even - 11 winners, 11 unforced errors - but the match swung completely in the other direction from the start of the second set, as Cibulkova's level shot up and Sharapova's slipped down. The No.20-seeded Cibulkova stormed out to a 5-0 lead, eventually closed out the set, 6-4, and raced through the third set to seal it, 36 64 61.
Sharapova's numbers in the last two sets combined weren't her best - 16 winners, 34 unforced.
"I went on the court and was more than 100% sure I could really beat her," Cibulkova said. "I had beaten her at a Grand Slam before. I had done it before. She knows me and how I play, but I also knew that she knew it would be a tough match. I was prepared to give 100% on the court today."
Cibulkova is now through to her first Australian Open quarterfinal, completing her set - she had already been to the quarterfinals or better at all the other majors. Her best result was the semifinals of the French Open in 2009 - she beat Sharapova in the quarterfinals before falling to Dinara Safina.
"This is what I'm really, really happy for, you know, I finally, finally made it here," Cibulkova said. "I had a great pre-season in December and I'm very happy I could show it on the court. It feels amazing."
Sharapova, who was treated for a hip strain between the second and third sets, talked about the loss in her post-match press conference - and she was very gracious when it came to crediting her opponent.
"I have a bit of a strain in the hip area, the trainer told me, but those aches and pains are expected when you spend a long time on the court, and you just have to play through it," Sharapova said. "I haven't been playing the best tennis of this tournament, but I found ways to win the last two matches.
"I tried to do that again today, but she played extremely well."
The former World No.1 and Career Grand Slam holder was asked to put her tournament in perspective.
"I think it's a success in that I'm back and I'm healthy," Sharapova said. "That's quite important. Otherwise I wouldn't have given myself a chance to play here. So I have to look at the positives and see where I've come from in four or five months. I haven't played a lot of tennis these six months.
"I would have loved to play more before playing a Grand Slam, but this is the chance I was given. I'm smart enough to acknowledge that I'm still lucky to be in the draw and give myself a chance to win it."