NEW YORK, NY, USA -- 19-year-old Czech Marketa Vondrousova moved into the fourth round of a Grand Slam event for the first time in her career, edging No.13 seed Kiki Bertens of the Netherlands, 7-6(4), 2-6, 7-6(1) in a marathon match at the US Open on Saturday.

"I fight for every ball," Vondrousova said, during her post-match press conference. "I was running a lot. So I think it was a great match. Yeah, it was so tough for me, but I'm happy to get through."

"I was just trying to play my game," Vondrousova added. "I think [Bertens] played really great tennis, but, yeah, I think it was my best match so far," the teenager admitted with a smile.

Vondrousova, the last player to receive direct entry into the main draw and the youngest player remaining in the field, came back from breaks down in the first and final sets to dominate tiebreaks in each, eventually prevailing after two hours and 20 minutes of play, and stopping the eight-match winning streak of Cincinnati champion Bertens.

The match was even until the very end, with Bertens having slightly more winners (33 to 29) and unforced errors (43 to 42) than Vondrousova. Bertens dominated the second set, which is why she ended the match with two more service breaks than Vondrousova.

But it was the Czech who came through when it mattered most at the business ends of the tiebreak sets, despite 10 double faults during the tilt. The teenager won her first WTA title last year in Biel and cracked the Top 50 earlier this year, but has slid to a current ranking of World No.103, and is thrilled with this milestone event in her career.

"I didn't have the best season, but I think this is coming back for me," Vondrousova stated. "This is my life result, so I'm very happy. I think hard work has paid off."

In her maiden Grand Slam fourth-round appearance, Vondrousova will face Lesia Tsurenko of Ukraine, who cruised past Katerina Siniakova of the Czech Republic, 6-4, 6-0 on Saturday.

"I just need to rest and I'll play my game," said Vondrousova, when asked about her next match. It will be the first meeting between Vondrousova and Tsurenko.

The young Czech went toe-to-toe with the seeded player for a long stretch of the first set, but Bertens took the initial lead after a lengthy game at 2-2, in which the Dutchwoman needed four break points before taking Vondrousova’s serve after a forehand error into the net by the Czech.

Bertens looked extremely solid on serve for the next few games, holding at love twice in a row with powerful deliveries and beautiful volleys and dropshots, en route to 5-3. But Vondrousova continued to find spots to place her effective forehand, steering her way to 5-4 behind that shot.

Suddenly, the Czech broke back for 5-5 with ease, firing a pinpoint forehand down the line to take the game. Then, in the tiebreak, Bertens double faulted on her first two service points to give Vondrousova a 3-0 lead, and the teenager cruised to the one-set lead from there, finishing off the set with a beautiful forehand volley for a winner.

Vondrousova continued to hold the momentum at the start of the second set, breaking Bertens in the opening game after Bertens bailed out from a barrage of the Czech’s forehands by dumping a drop shot into the net.

However, after holding for 2-0, Vondrousova suddenly lost the efficacy on her service, while Bertens immediately began to dominate with her serve and powerful forehand. Bertens plowed through two quick service games while breaking Vondrousova at love in between, at one point reeling off 11 straight points while getting back on serve and leading 3-2.

Vondrousova fired more errors in her next service game, allowing Bertens to break again for 4-2. The Dutchwoman held for 5-2 with an ace, and then broke Vondrousova at love once more to claim the second set after winning six straight games.

Bertens kept her wits about her in the opening stages of the decider, claiming the first break of the set by firing a backhand passing shot down the line behind the Czech to lead 4-2. But Vondrousova struck back straight away, using her big lefty forehand to force Bertens into a netted error, putting the set back on serve.

It was then Vondrousova’s turn to take control in the roller-coaster set, fighting back from 40-0 with huge returns to break for 6-5 and serve for the match. But Bertens slammed stunning backhand winners on the final three points of that game to break right back, sending the third set into a decisive tiebreak.

Vondrousova won the first two points on her serve via netcord-affected winners to lead 2-1, and after the Czech went up 3-1 by cracking open a rally with a blistering forehand passing shot for a winner, she rolled from there. The teenager claimed the final seven points of the tiebreak, rolling past the frustrated Dutchwoman into her first fourth-round showing at a Grand Slam.