PALERMO, Italy -- Arantxa Rus continued her run at the Palermo Ladies Open on Thursday, as the Dutchwoman upset No.3 seed Viktoria Kuzmova of Slovakia, 6-4, 6-4, to reach the quarterfinals.

Rus, ranked World No.130, earned a spot in her first WTA quarterfinal of 2019 with her upset of the 49th-ranked Kuzmova, after just over an hour and a half of play.

"I’m working hard with my coach, and when you see the results, it’s really good," Rus said, after her win.

Read more: Rus rolls past Hesse in Palermo

On a hot day in Sicily, it was Rus who won 70 percent of points on Kuzmova's second serve, and she broke the Slovak six times off of her ten break points for her first Top 50 win of the year. Kuzmova had six double faults in the clash, and her 25 winners were undone by 34 unforced errors.

"The conditions were really tough," said Rus. "I tried to prepare good for that. Then in the match, I just tried to stay aggressive and stay calm with the heat, and I think I played good, aggressive on important points."

"I played a lot of heavy balls," Rus added. "[Kuzmova] likes to attack, and when she attacks, she’s a really good player."

Rus will face either Paula Badosa of Spain or Hungarian lucky loser Fanny Stollar in the quarterfinals.

The clash started with a staggering six consecutive service breaks, as both players were using strong groundstrokes to take control on return. Rus broke the spell with a hold for 4-3, saving a break point in the process. Kuzmova then leveled with her first hold for 4-4 after a closely contested four-deuce game.

Rus put the pressure firmly back on Kuzmova as the Dutchwoman had her first commanding service game, a love hold for 5-4. In the next game, Rus pulled to 15-30 with a strong backhand, and Kuzmova then double faulted to give Rus two set points. On her second opportunity, Rus clinched the first set with a forehand passing winner crosscourt.

"The beginning of the match, was a little bit of mistakes from both sides, we broke each other, and at the end of the first set, I played better and better," Rus stated.

Kuzmova started the second set well, as the Slovak used exceptional forehands to earn an early service break, going ahead 2-1.  Kuzmova had to survive another lengthy game on her serve before consolidating, but after a winning backhand dropshot to hold for 3-1, she appeared to hold the upper hand in the set.

However, after swift service games to stay within touching distance, Rus grabbed her chance at 4-3, punching a forehand volley for a winner on break point to level the set at 4-4. Aggressive played by the Dutch lefty helped her garner a hold for 5-4, and, suddenly, Kuzmova was serving to stay in the match.

Rus again moved ahead on the Kuzmova service for the second time in a row, and an error-forcing return by the Dutchwoman gave her a match point. There, Kuzmova double faulted, allowing Rus to book her spot in the quarterfinals.