Unseeded Svetlana Kuznetsova of Russia knocked off fourth-seeded Belinda Bencic of Switzerland in straight sets in a quarterfinal of the Qatar Open in Doha on Thursday.

Kuznetsova has a history of success in the tournament. A runner-up in 2004 and again in 2007, she has 19 match wins in 11 appearances in Doha.

"I have amazing memories. It was my first time when I beat Justine (Henin) here (in the 2004 semifinals), and it was like I was a kid, I was 19," the 34-year-old Kuznetsova told reporters afterward. "I raised from No. 30-something to No. 13 or No. 14, and it was amazing. It was so long ago it was like another life, but it really happened to me -- I didn't watch it in the movies.

"And here I'm back again in the semis. I didn't expect it that early. I've been working hard for this, and it's nice that the work pays off."

Kuznetsova, ranked 46th in the world, won 6-4, 6-4 over Bencic, who is ranked No. 9. Kuznetsova was broken just once in four chances, while converting nine of 12 chances to break Bencic's serve.

In the semifinals, Kuznetsova will face Aryna Sabalenka of Belarus, the tournament's ninth seed. Sabalenka needed three sets and nearly 2 1/2 hours to fend off Saisai Zheng of China 3-6, 7-6 (2), 6-3.

Sabalenka was asked afterward how she managed the comeback after losing the first set.

"Honestly, I don't know," she said with a laugh. "I was just trying to push myself to fight for each point. And she was playing really well, moving really good and there was so many balls coming back on my side.

"I was just trying to go for it, like go through everything, especially with conditions here. And I'm just happy that I could handle this pressure and could find the way how to win this match in these conditions."

The other semifinal will feature world No. 1 Ashleigh Barty of Australia against eighth-seeded Petra Kvitova of the Czech Republic.

Barty, the tourney's No. 1 seed, defeated Garbine Muguruza of Spain in three sets, 6-1, 7-6 (4), 6-2.

"I love testing myself against Petra," Barty told WTA.com afterward. "We have fantastic battles every time."

Barty came from down a break to force a tiebreaker in the second set, then won the first five points of the tiebreaker. In the third set, Barty was broken once but also broke Muguruza's serve three consecutive times to close the match.

Kvitova beat unseeded Ons Jabeur of Tunisia 7-6 (2) and 7-6 (4). Jabeur had beaten Karolina Pliskova, a former world No. 1 and the tournament's third seed, in three sets to make the quarterfinals.