ROME, Italy -- Polona Hercog of Slovenia claimed a signature win in the second round of the Internazionali BNL d’Italia on Thursday, stunning No.5 seed Kiki Bertens of the Netherlands, 6-4, 6-4.

With the one-hour and 36-minute victory, World No.50 Hercog moved into the round of 16 in Rome for the second time in her career, matching her run from back in 2011. Hercog picked up her second win in three meetings with Bertens, having also beaten the Dutchwoman in Dallas in 2012.

Moreover, Hercog at last picked up her second career victory over a Top 10 player in her 33nd match against members of that cohort. Her previous Top 10 win came over then-World No.7 Marion Bartoli back in 2012 Charleston.

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"It’s been a while since I’ve played Kiki, since the end of last year, I think she’s a good player and a nice person as well," Hercog told the media, after the tilt.

"I really enjoyed it out there, I did the tactics and everything right," the Slovene continued. "I was just trying to stick to my plan, and it really worked well today."

Against Bertens, Hercog out-winnered her opponent by 19 to 11, converting five of her ten break points on the day, as she broke a 22-match losing streak against Top 10 opposition.

World No.8 Bertens, twice a semifinalist at Rome, including last year, was playing her first WTA match since a third-round loss to Zheng Saisai at Doha in February. Despite a mid-match run where she claimed seven of eight games, the Dutchwoman was undone by 31 unforced errors, and could only win 47 percent of points when she got her usually exceptional first service into play.

In the round of 16, Hercog will take on No.12 seed Marketa Vondrousova of the Czech Republic. Hercog will be facing the 2019 Roland Garros finalist for the first time, in a bid for her first quarterfinal at a Premier 5 tournament. Hercog has reached a WTA quarterfinal 27 times in her career, but only once at a Premier tournament (2012 Charleston, where she reached the semifinals).

"[Vondrousova] had great success on clay last year, and definitely a good player, a lefty," said Hercog. "I will have to do a little bit of different things. Of course, I’m going to set up the plan with my coach tomorrow, and I’m really looking forward to the next challenge."

Hercog put her stamp on the match right away, wrapping up a lengthy rally with a forehand crosscourt winner to earn a break in the very first game. The Slovene continued to control the opening stages with fabulous power play, firing an ace to hold for 2-0, then earning a second break, this time at love, to move ahead 3-0.

Bertens tightened up her game, lowering her error count as the set progressed, and saved five break points during a protracted 4-0 game, but it would not be enough as Hercog converted her sixth break point in that battle to lead 5-0. Serving for the set, though, Hercog could not close, as Bertens got on the scoreboard at last to avert the bagel.

Hercog’s second chance to serve out the set at 5-2 also fell by the wayside, as Bertens claimed another break, pulling herself to 5-4 as her comeback continued. The Slovene, though, eventually picked up three set points in her third attempt at polishing off the opening frame, finally closing it out with an error-forcing forehand.

Despite losing the opening frame, Bertens came into the second set with momentum, having won four of the previous five games. The fifth seed continued to progress in that manner, breaking Hercog for 2-0, then consolidating for 3-0.

After dropping seven of the last eight games, though, Hercog started her own streak. After gritting out a challenging hold to get on the board at 3-1, Hercog took advantage of two successive double faults by Bertens en route to triple break point, then blasted a backhand passing winner to break at love and get back on serve at 3-2.

Hercog began to mix deft dropshots in with more precise power hitting, and claimed another break at love to reclaim a definitive lead at 4-3. The Slovene won 13 points in a row before Bertens could quell that run, but it was not enough to prevent Hercog from holding for 5-3.

At 5-4, Hercog zipped to triple match point, and one final divine dropshot sealed another love hold, at last giving the unseeded player an addition to her collection of Top 10 wins.