Australian Open champion Sofia Kenin crashed out of the WTA event in Abu Dhabi, losing in three sets to number nine seed Maria Sakkari in the quarter-finals on Monday.
After top seed Kenin took the opening set 6-2, the Greek bounced back by galloping through the next two 6-2, 6-0 winning the last 10 games in a row to complete her fifth Top 5 win and book a semi-final meeting with the Belorussian Aryna Sabalenka.
"Beating these players this week it means a lot," said Sakkari after her win.
"I'm playing players that I've never played, like (Garbine Muguruza) yesterday, so I have a better idea if I play them again.
"So in general it gives me a lot of confidence starting the year like that and I'm super happy to travel to Australia with some good matches with me."
The Australian Open begins in Melbourne on February 8.
Kenin survived a match point in the previous round before getting the better of Yulia Putintseva but the American found the new, improved Sakkari a different proposition.
Kenin swept through the opening set but the match changed completely when Sakkari held service for 3-2 in the second and then broke Kenin to go 4-2 ahead.
The Greek, ranked 22 in the world, pounded the lines to take the set and then bulldozed the third, inflicting a rare bagel on the world number four.
"I think that one of the things that really helped me is that I realised that my ball is pretty heavy," said Sakkari.
"I have a lot of power and I have been using it the right way.
"Up until last year I couldn't really control my power so I had to take a little bit of pace off because I was hitting too hard and I was missing many shots.
"So I think I've found a way and I've found my real pace on the court. When I have an opportunity I go for it and that builds confidence."
In the other semi-final, 18 year-old Ukrainian Marta Kostyuk will meet another unseeded player, the Russian Veronika Kudermetova who beat world number five Elina Svitolina 5-7, 6-3, 7-6(3).
World number 99 Kostyuk came back from a first-set horrow show to beat the Spaniard Sara Sorribes Tormo 0-6, 6-1, 6-4, and reach the first WTA semifinal of her career.
Kudermetova of Russia shocked Svitolinain a two-and-a-half-hour thriller to claim the fifth Top 10 win of her career.
"I tried to play aggressive, because you know Elina, she has such good defense," said Kudermetova.
"If you want to win, you need to attack, you need to go to the net, finish the point, because she runs unbelievably. You need to do something aggressive to win the points."