Jessica Pegula notched yet another big win this season as she stunned No.2 seed Naomi Osaka in the second round of the Internazionali BNL d'Italia on Wednesday, 7-6(2), 6-2.

"I knew I was right there," Pegula told the press, after her win. "I knew if I could just hang in there and play my service games smart, I could get opportunities on her serve. I did in the tiebreak especially. I thought I toughed out the first set mentally, and then the second set I started to play better."

World No.31 Pegula's surge up the rankings in 2021 has been accompanied by the first four Top 10 wins of her career. Her 87-minute victory over Osaka, the World No.2 and four-time Grand Slam champion, is now her fifth Top 10 win, and the best of her career by ranking.

Making her Rome main-draw debut this week, Pegula avenged a loss to Osaka in their only previous meeting, which came in Beijing in 2019. This time around, Pegula saved three set points in the opening frame en route to the upset.

Overall, Pegula out-winnered the former World No.1 by 22 to 20, and Osaka came unglued with 37 unforced errors, 16 more than Pegula's total. Pegula converted four of her five break points in the match as she romped through the second set to upend the second seed.

"I know that she's a strong, powerful player that she could come back at any time," Pegula said. "I was glad that I kind of closed it out there quicker in the second set when I had the chances."

At first, Osaka had things all her way as she built up an early 3-0 lead, but Pegula charged back straight away to pull back to parity at 3-3. Pegula was then in peril on serve at 5-4, after a forehand winner down the line by Osaka gave the No.2 seed a set point, but Pegula gritted her way through a tough game to hold on for 5-5.

Osaka had two more set points at 6-5, but a forehand winner and an error-forcing groundstroke by the American helped her erase those chances as well, queuing up a decisive first-set tiebreak.

Pegula upsets Osaka for best career win: Rome Highlights

2021 Rome

It was in the breaker where Pegula took control, slamming a forehand return winner to earn a mini-break at 3-2, then drawing errors from Osaka the rest of the way home. A third consecutive backhand miscue by Osaka gave Pegula a 6-2 lead and four set points; Pegula only needed one as Osaka fired a forehand long to cede the one-set lead.

After an early exchange of breaks in the second set, Pegula moved ahead by 4-2 after a solid return game, and the unseeded player never looked back from there, firing a backhand return winner to earn her third break of the set in the final game and collect a top-notch win.

"It kind of just gradually happens, and all of a sudden the confidence is there where you feel comfortable," Pegula said. "You can feel the difference of your mindset and how you're thinking, how you go about things. I think I have adjusted really well, because a lot of these big tournaments I have never played before, and it's all a new experience, which is also a way to make it fun and make it exciting."

Earlier, World No.1 Ashleigh Barty prevailed in her opening match at the Internazionali BNL d'Italia on Wednesday, defeating Yaroslava Shvedova 6-4, 6-1 to reach the round of 16.

Despite the routine scoreline, it was not all smooth sailing for the top seed early, as she had to fight through a challenging first set before notching the one-hour and 18-minute victory over the former World No.25 from Kazakhstan who is on the comeback trail.

"Room to improve without a doubt, but overall I’m happy to get through and get another opportunity tomorrow to work on a few things," Barty said after her win. "I feel like I’m really getting myself into the tournament here in Rome. I think it’s such a beautiful, iconic event and I’m really excited now that I get another opportunity tomorrow."

The tour leader in match-wins so far this season with 26, Barty has now matched her best-ever performance in Rome in her third appearance at the event. Barty reached the third round in her last showing in 2019.

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Barty rebounded from a shaky start to the match, where she fell behind an early break and was pressed by Shvedova through the majority of the opening frame. Nevertheless, the Australian overcame a spate of errors to take command as the match progressed, and eventually converted five of her six break points, fired seven aces, and won 64 percent of points returning Shvedova's second serve.

World No.665 Shvedova, in the main draw on a protected ranking, defeated Martina Trevisan in the first round this week for her first WTA main-draw victory since her return to the tour last year, following surgery and the birth of her children. Her run ended today as she was unable to claim the second Top 5 win of her career.

More unforced errors than expected flew from Barty’s racquet in the early stages of the opening set, and after a wide forehand in the first game, Shvedova had already broken the World No.1. Strong deliveries by Shvedova helped her survive a break point in the next game, and she continued to use her serve to power through games with aplomb as she held her lead through 4-2.

However, Barty tightened up her game at that point and turned the set around, starting with a break back for 4-4 after miscues by Shvedova. Then, faced with another break point at a tense moment, Barty swiped that chance away with two straight aces en route to a hold for 5-4. Rejuvenated by those escapes, Barty dominated with her forehand in the next game to force errors and break again for the one-set lead.

Shvedova made one last charge at the start of the second set, breaking Barty to edge to 2-1. But it was the World No.1 who dominated on return in that set, working with her fierce forehand to break Shvedova in the Kazakh’s last three service games and race to 5-1. Now in full control, Barty swept through an easy service game to close out the win, completing the clash with an error-forcing backhand.

"Slava’s got a game that can take it away from you quite quickly and she got a fast start," Barty said. "I was just trying to work my way back in and give myself a chance."

Current World No.1 Barty was joined in the round of 16 by former World No.1 Karolina Pliskova. The 9th-seeded Czech, who won the Internazionali BNL d'Italia title in 2019 and was runner-up last year, dispatched Anastasija Sevastova, 6-2, 6-3, to claim her first win of the week.

Pliskova and Sevastova had a deadlocked 2-2 head-to-head coming into their tilt, but it was Pliskova who was in control of their latest encounter as she eased to victory in an hour and 11 minutes of play.

Powerful server Pliskova won 76 percent of her first-service points, and she was just as impressive on return, holding 13 break points on the day and converting six of those.

Photo by WTA/Jimmie48

Pliskova had minimal trouble in the first set as she stormed to a 5-2 lead, then rocketed an ace to set up double set point. A double fault erased her first chance, but on the second, Pliskova found a forehand winner down the line to collect the one-set advantage.

The No.9 seed quickly jumped ahead by a double-break in the second set, leading 4-1, before Sevastova at last found her returning rhythm and clinched her first break of the day for 4-2. Pliskova slammed more down-the-line winners to reclaim the double-break and lead 5-2, but, serving for the match, the Czech could not finish the job and Sevastova moved to 5-3.

Pliskova, though, eventually came through in the subsequent game. A stirring shot in the corner forced an error from Sevastova and gave the Czech match point, and though the Latvian saved that chance, a netted backhand gave Pliskova a second opportunity. There, a Sevastova forehand found the net, and Pliskova made safe passage into the third round in Rome once again.

Vera Zvonareva, though, pulled off an upset over another Czech, as the Russian veteran outlasted No.11 seed Petra Kvitova 6-4, 3-6, 6-4 in two hours and 23 minutes.

Both former World No.2s, Zvonareva and Kvitova had squared off six times previously, with a 3-3 split in their head-to-head. But their last meeting came nearly a decade ago at the 2011 WTA Finals.

Despite a great disparity in their current rankings, 113th-ranked Zvonareva came through with the victory by converting seven of her eight break points, which included three breaks of big-serving Kvitova in the decider.

Zvonareva stuns Kvitova in throwback win: Rome Highlights

2021 Rome

In the opening set, Zvonareva was broken at love in her first chance to serve for it at 5-2, but the Russian at last grabbed four set points at 5-4. Kvitova fended off the first three with winners, but on the fourth, Zvonareva finally pierced exceptional defense by the Czech with a down-the-line winner to scoop the one-set lead.

Kvitova fired back in the second set. After dropping serve in the first game, the two-time Wimbledon champion broke Zvonareva twice down the stretch to get to one set apiece, punctuating that frame with a backhand winner.

In the final set, Zvonareva reeled off five straight games from 0-2 to 5-2, but again was unable to serve out the match at her first time of asking, and missed a match point in each of the 5-2 and 5-3 games. The 36-year-old mother, though, converted her third match point to break serve for the win, reaching the Rome round of 16 for the first time since 2008.