San Diego (California), Oct 15 : World No.1 Iga Swiatek of Poland scored a dominant 6-0, 6-3 win over teenager Coco Gauff to advance to the semifinals of the San Diego Open, extending her undefeated record against the No. 8 from the US to 4-0. Swiatek, who is in her third consecutive semifinal, will face another American, world No.6 Jessica Pegula, in the semifinal. Pegula booked her last-four spot by defeating Madison Keys 6-4, 7-5 in the first meeting between two of the top three-ranked Americans on the Tour. The biggest difference between the two quarterfinal opponents on Friday evening was in offense, where Swiatek has improved the most this year. Swiatek pocketed the first eight games before the American teenager held serve to 2-1 in the second set. However, Swiatek finished off the match in 65 minutes with 13 winners to nine unforced errors while breaking Gauff five times. Gauff hit 17 winners to 26 unforced errors and could not convert on the three break-point opportunities she earned. Dealt a tough draw here, Swiatek handled Tokyo finalist Zheng Qinwen in three sets in her opening match and followed it up with a clinical performance to beat Gauff. In every tournament at which she has played Gauff, Swiatek has gone on to win the title, having beaten the American at 2021 Rome, 2022 Miami, and 2022 Roland Garros, according to wtatennis.com. The victory is Swiatek's 62nd of the season and 40th on hard court. Having won Indian Wells, Miami, and the US Open, the 21-year-old is now 22-1 in the United States this season. The first set against Gauff was her 20th 6-0 "bagel" set of the season, the most since Serena Williams posted 25 in her 2013 season, according to the website. "I've played (Swiatek) so often that I kind of know what to expect," Pegula said of her semifinal opponent. "She plays super athletic, aggressive, defends really well. She does everything at a really high level. She plays a little bit different than the girls and sometimes that can be the difference. You're not used to playing someone like her. "I'd like to say maybe it's better playing her at the end of the year, but I don't know. We'll see how the match goes." Swiatek and Pegula will clash for the fourth time this season. Swiatek has swept their sets, winning in the Miami semifinals, Roland Garros quarterfinals, and US Open quarterfinals last month. "Jessie is one of the most solid players on tour so it's always hard," Swiatek said. "Our matches are always physical and really tight. Even though sometimes the scores are one way, you can see during the games we always have deuces and any point can matter. I'm pretty happy that we're going to play against each other because it's a test for me of where my level is because she's really, really solid." /IANS