World No.1 Iga Swiatek is up to 37 victories in a row, but her latest win came after an extended struggle. Swiatek of Poland overcame Dutch lucky loser Lesley Pattinama Kerkhove 6-4, 4-6, 6-3 in the second round of Wimbledon on Thursday.

Swiatek of Poland needed just over two hours on No.1 Court to quash the spirited effort by 30-year-old Pattinama Kerkhove and move into the third round at SW19 for the second straight season.

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Words from the winner: "For sure my confidence, I build it during this season," Swiatek said afterward. "It's getting better and better on every tournament.

"I would say the grass is pretty tricky for me, I'm not going to lie. I guess you can see that I'm not playing maybe as efficiently as on other surfaces. Basically my confidence is getting better overall. But this tournament is tricky and I'm still feeling out how to play the best game here."

Swiatek prevails again: With the win over Pattinama Kerkhove, 21-year-old Swiatek surpassed Monica Seles’ 36-match winning streak from 1990 and matched Martina Hingis’ 37-match winning streak from the beginning of the 1997 season. 

Swiatek’s run has led to six consecutive titles, spanning both hard courts (Doha, Indian Wells, Miami) and clay (Stuttgart, Rome, Roland Garros) and includes two wins for Team Poland at the Billie Jean King Cup.

Dutch challenge: However, World No.138 Pattinama Kerkhove severely tested the World No.1 in the Dutchwoman's first match against a Top 10 player. Pattinama Kerkhove, who was in the Wimbledon second round for the second straight year, was unfazed in just the sixth Grand Slam main-draw match of her career.

"I was just, like, 'Okay, go for it,'" Pattinama Kerkhove said in press. "Every point, every ball, I had to do it. When she's attacking, it's so tough to take the points to defend against her. So my goal was just like go for every shot, go for every ball, and play aggressive. I did. Actually, it worked well."

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Pattinama Kerkhove took an early 4-2 lead behind sturdy forehands, but Swiatek began to find more reliable groundstrokes as the opener progressed. Using her own booming forehand, Swiatek swept the last four games to take a one-set lead.

But Pattinama Kerkhove also claimed the first break in the second set, and the Dutch player did not yield from 4-3 up this time. The World No.138, who lost in the final round of qualifying before taking injured Danka Kovinic's spot in the main draw, saved both break points she faced in the second set, leveling the match.

In the end, though, it was Swiatek who took charge in the decider, breaking for 3-1 with a rally forehand winner. That would be all the top seed needed to clinch the victory, and she prevailed with 31 winners to Pattinama Kerkhove's 15.

Next up: Swiatek will take on France’s Alizé Cornet in the third round, after Cornet dispatched American Claire Liu 6-3, 6-3 earlier on Thursday. It will be the first meeting between Swiatek and 32-year-old veteran Cornet.

Former World No.11 Cornet is playing her 62nd consecutive Grand Slam tournament, which ties Ai Sugiyama of Japan for the Open Era record. Cornet’s best Wimbledon result came in 2014, when she shocked No.1 seed Serena Williams to reach the Round of 16.

Pegula outlasts Dart

Jessica Pegula also spent some time on upset alert on Thursday, but the No.8 seed from the United States pulled off a comeback win over British hope Harriet Dart 4-6, 6-3, 6-1 on No.2 Court.

Playing her first tournament since reaching her second Grand Slam quarterfinal of the year at Roland Garros, Pegula took 1 hour and 51 minutes to hold off World No.94 Dart, who reached grass-court quarterfinals in two of her last three events on tour.

Despite Dart's solid form of late, Pegula was able to charge back after dropping the first set, converting seven of her 11 break points as she booked a third-round spot at Wimbledon for the first time in her career. Meanwhile, Dart fell to 0-6 against Top 10 opposition.

Pegula will take on former Top 20 player Petra Martic of Croatia in the third round, after Martic defeated Slovakia's Kristina Kucova 7-6(4), 6-3. Martic has a 4-1 head-to-head lead over Pegula.