2021-07-23 08:04:36 GMT+00:00 - In his ATP Tour debut, Vit Kopriva of the Czech Republic rallied to upset Canadian top seed Denis Shapovalov 2-6, 6-3, 6-2 Thursday in the Round of 16 of the Swiss Open Gstaad. Shapovalov smashed 11 aces compared to Kopriva"s three, but also committed 10 double faults. Kopriva also won 82 percent of his first-serve points (27 of 33) en route to his surprise victory. Kopriva will advance to the quarterfinals to meet Sweden"s Mikael Ymer, who also won in upset fashion Thursday with a 6-7 (6), 7-6 (7), 6-4 victory over Spanish No. 8 seed Feliciano Lopez. Due to the two tiebreaks, the match lasted roughly 2 1/2 hours. No. 3 seed Casper Ruud and No. 6 seed Benoit Paire took care of business, with the Norwegian Ruud defeating Austrian Dennis Novak 6-4, 7-6 (5) and Paire advancing when Dutch foe Tallon Griekspoor retired in the second set. Plava Laguna Croatia Open Umag A pair of highly seeded Serbs advanced to the quarterfinals in Umag, Croatia. No. 2 seed Dusan Lajovic took care of Spain"s Bernabe Zapata Miralles 7-5, 6-4, while No. 3 seed Filip Krajinovic bested Radu Albot of Moldova 6-4, 6-2. Thursday"s results meant the top four seeds in Umag all reached the quarterfinals. Krajinovic will square off with Spanish No. 7 seed Carlos Alcaraz, who handled Slovakia"s Andrej Martin 6-3, 6-1. Meanwhile, German qualifier Daniel Altmaier won his second straight in the main draw by beating No. 8 seed Gianluca Mager of Italy, 4-6, 6-1, 7-5. Altmaier will meet Lajovic in the quarters. Mifel Open The top three seeds advanced to the semifinals in Los Cabos, Mexico, after fairly breezy quarterfinal victories. No. 1 seed Cameron Norrie of Great Britain made quick work of Ernesto Escobedo 6-1, 6-1, while second-seeded John Isner of the United States defeated Australian Alex Bolt 6-3, 6-4. No. 3 seed Taylor Fritz dispatched No. 6 seed Steve Johnson 6-4, 6-2 in a battle of U.S. players to claim his spot in the semis. Norrie and Fritz will face off in the semifinals while Isner will play Brandon Nakashima of the United States, who outlasted fifth-seeded Jordan Thompson of Australia 6-3, 4-6, 7-6 (4).