(Photo credit: Geoff Burke-Imagn Images)

In her first match with new clay-court coach Francisco Roig, former World No. 1 Iga Swiatek cruised past Laura Siegemund of Germany 6-2, 6-3 on Wednesday at the Porsche Tennis Grand Prix in Stuttgart, Germany.

Swiatek, a two-time champion at Stuttgart who is seeded No. 3, failed to capitalize on an early break in the opening set, but rebounded by breaking Siegemund in the sixth and eighth games. In the second set, the six-time Grand Slam champion missed out on another early break but again broke her opponent in the eighth game to take a 5-3 lead before closing out the match. Swiatek, who had a first-round bye, is on to the quarterfinals.

Qualifier Zeynep Sonmez of Turkey pulled off a sizable upset, taking down fifth-seeded Jasmine Paolini of Italy 6-2, 6-2 in a one-hour, 16-minute match. Snmez landed 72% of her first serves and also won 62.5% percent of second-return points, while Paolini failed to convert her lone break-point opportunities and won just 41.8% of total points.

Fourth-seeded Elina Svitolina of Ukraine was among the other winners, dominating Eva Lys of Germany 6-1, 6-0. Sixth-seeded Mirra Andreeva of Russia took down defending champion Jelena Ostapenko of Latvia 5-7, 6-2, 6-4, American qualifier Alycia Parks defeated German wild card Noma Noha Akugue 6-4, 6-2, and Linda Noskova of the Czech Republic outlasted Zhang Shuai of China 5-7, 6-1, 6-4.

Rouen Metropolitan Open

Unseeded Katie Boulter of Great Britain pulled off an upset of No. 3 seed Jaqueline Cristian of Romania, winning 7-6 (5), 4-6, 6-1 to advance to the quarterfinals at Rouen, France.

Boulter, who has won just once on the WTA Tour, survived a tough first set that saw her take a 5-0 lead in the tiebreaker, only for Cristian to save five set points before Boulter prevailed. Cristian rebounded in the second set, but Boulter cruised in the third set, breaking Cristian twice en route to the win.

Top-seeded Marta Kostyuk of Ukraine dropped the opening set to unseeded American Caty McNally, then bounced back for a 2-6, 6-2, 6-1 victory to reach the quarterfinals. Kostyuk will face fifth-seeded American Ann Li, who notched a 4-6, 6-2, 6-3 triumph over unseeded Kamilla Rakhimova of Uzbekistan. Unseeded Tatjana Maria of Germany upset No. 9 seed Elsa Jacquemot of France 6-4, 6-3. Other winners included No. 2 seed Sorana Cirstea of Romania, Anna Bondar of Hungary and Oleksandra Oliynykova of Ukraine.

--Field Level Media