ISTANBUL, Turkey -- Polona Hercog of Slovenia advanced to her first WTA semifinal in over two years, surviving a comeback by No.2 seed Svetlana Kuznetsova of Russia and prevailing 6-1, 1-6, 7-5 at the TEB BNP Paribas Istanbul Cup on Friday.

Hercog picked up her first win over the two-time Grand Slam champion in their three meetings, overcoming a disastrous second set to claim victory in two hours and 19 minutes.

"I wasn't really thinking about a good result when I came here - I was just trying to take it step by step," Hercog said after the match. "I was winning a match here, a match there in my previous tournaments...and I was always injured for a couple of months this year. I'm really satisfied with what I'm doing right now and it's really positive."

Both players finished the match with 21 unforced errors, though Hercog had 31 winners, while Kuznetsova had only eight.

Hercog will now face Maria Sakkari of Greece in the semifinals. Sakkari eliminated Dutch qualifier Arantxa Rus earlier on Friday, 6-3, 7-6(6).

The first set was an absolute indication that the result might go Hercog’s way, as the Slovenian dominated the proceedings, hitting 20 winners in the set, to Kuznetsova’s three. The powerful Hercog forehand was on song in the opening frame, and Hercog rampaged through the set behind that wing.

After holding for 3-0 with a forehand winner, Hercog cracked the set open by claiming a double-break advantage in a marathon fourth game, ultimately claiming the 4-0 lead on her seventh break point of the game by forcing an error with an overhead.

The protracted game caused the set to be a lengthy 45 minutes, but the score was well in Hercog’s favor, and the World No.75 wrapped up the 6-1 set after a Kuznetsova backhand sailed wide.

"I knew I had to be really focused and use every chance I had because she's a really good player and she can just feel it when you're not feeling at your best," Hercog added. "I was just trying to be as aggressive as possible, using the spin and using the court."

The tables turned in the second set, as Kuznetsova displayed the experience which led her to titles at the 2004 US Open and 2009 Roland Garros, as well as a career-high ranking of World No.2.

The Russian had only three winners in this set as well, but she also hit only two unforced errors, and frequently won the important points, breaking thrice on five opportunities.

By contrast, the searing skills demonstrated by Hercog in the first set dissipated, as the Slovenian could hit only one winner in the second set. Kuznetsova raced to a 4-0 lead of her own, and broke Hercog again for 5-1 with a bludgeoning forehand winner. In the following game, a long service return off of the Hercog racket let Kuznetsova level the match at one set apiece.

"I'm still on the way where I'm developing my game and the focus on court, so it's not always easy to hold the focus for the whole match," Hercog said of the second set. "It's something I'm really working for - to become better in that."

Given the one-sided nature of the two sets, the decider was completely up for grabs. Kuznetsova nearly held onto the momentum, as strong defense by the Russian gave her two break points in the opening game, but the power game of Hercog pulled her through to hold for 1-0.

Kuznetsova then claimed first blood in the set, taking a 4-3 lead after Hercog dropped serve due to a double fault and a netted groundstroke error. But Hercog quickly struck back for 4-4 after consecutive backhand errors by the Russian.

Hercog then swiftly dropped serve in the next game, the Slovenian’s errors giving Kuznetsova the chance to serve out the match. But the Russian was unable to complete the victory, dropping serve at love with a backhand error into the net, and putting the set on even terms at 5-5.

After four straight breaks of serve, Hercog clinched what seemed like a pivotal hold for 6-5 with a rocketing forehand winner down the line.

Indeed, it turned out to be the decisive moment, as Kuznetsova’s errors stayed present, and the Russian dropped serve for the third consecutive time. Hercog squealed with joy as she reached the final four of a WTA event for the first time since 2015.