Before a sold-out crowd in Cincinnati on Tuesday, 19-year-old British tennis star Emma Raducanu trounced 23-time Grand Slam champion Serena Williams in the first main draw match of the Western & Southern Open. Raducanu, currently ranked No. 1 in women’s tennis after winning last year’s U.S. Open, beat Williams in straight sets, 6-4, 6-0, in just under 90 minutes of play. “We all need to honor Serena for her amazing career,” Raducanu said, according to The Athletic. “I’m just grateful for the experience.” Williams exited the court quickly after her defeat, waving to the crowd roaring for her. The 40-year-old player, who has won two Western & Southern Opens, announced in Vogue last week that she would retire after the forthcoming U.S. Open, her prime target, according to coach Eric Hechtman, and swan song. The tournament is set to run in Flushing Meadows, New York, Aug. 29 through Sept. 11.