ADELAIDE, Australia - Aryna Sabalanka scored her first big upset of the 2020 season, knocking out No.2 seed Simona Halep, 6-4, 6-2 to reach the Adelaide International semifinals.

Sabalenka ended 2019 with title runs at the Dongfeng Motor Wuhan Open and Hengqin Life WTA Elite Trophy Zhuhai and, though she endured personal tragedy during the off-season, showed flashes off that form in the one hour and nine-minute win over the reigning Wimbledon champion on Centre Court.

From 4-4 in the first set, Sabalenka won seven straight games to build a 6-4, 5-0 lead, before she ultimately closed out the two-time Grand Slam champion a short time later. 

"I knew she'll fight until the end -- it doesn't matter what the score. When the score was 5-Love, I kind of expected that she'll try to do everything she can to come back in the match," Sabalenka said.

"I wasn't really disappointed after that two games. That helped me to stay in the match and to not lose my mind. I'm happy with this win, especially against big fighters like Simona and the great players. [It] feels good."

The Belarusian was on the brink of defeat in her first round against the always dangerous Hsieh Su-Wei, but played more stable tennis against American qualifier Bernarda Pera on Wednesday to book the clash with Halep, who dispatched hometown favorite Ajla Tomljanovic in her first singles match of the season.

"After the first week in Shenzhen, I didn't feel really well on the court. I'm so happy that I got wildcard here and I have some opportunities to play some matches, especially before the Australian Open," the Belarusian continued.

"It's really important every match for me because I'm kind of find[ing] this fight[ing] spirit. It helps me a lot."

Halep had won their two previous matches - both of which occurred in 2018 - and broke serve to start the match. Sabalenka reversed a 40-15 deficit in the next game to break back and navigate through some tricky games to take a 4-2 lead in the opening set.

While the former World No.1 soon leveled, Sabalenka responded with an emphatic love hold and swiftly took the set with a fearsome forehand return winner.

The No.6 seed only got stronger in the second set, racing out to a 5-0 lead before Halep finally got on the board, and while the Romanian clawed back one of the two breaks, Sabalenka proved too strong as she broke once more to secure victory.

It was an almost picture-perfect match from the former World No.9, who struck 30 winners to just 10 unforced errors. While Halep kept her score sheet cleaner with six unforced errors, she only managed 12 winners in the face of her opponent's unstoppable offense.

Standing between Sabalenka and a first final of the season is Ukrainian youngster Dayana Yastremska, who opened play on Thursday with a straight-set win over Donna Vekic.

"She's doing really well. She's aggressive player. It will be really quick tomorrow there, but I like this game," Sabalenka assessed. "I think it's interesting to watch powerful players.

"We'll see what happens. I can't control the result, right? We can just control ourselves. I'll be there. I'll be fighting for every point. Who knows what's gonna happen."

2020 Adelaide Highlights: Sabalenka shocks Halep in upset