Tokyo, July 27 : Four-time Grand Slam champion, Naomi Osaka's run at the Tokyo Olympic Games came to an end with the Japanese star losing to 2019 French Open runner-up, Marketa Vondrousova of the Czech Republic, 6-1, 6-4 in the third round on Tuesday, With Naomi's exit, the top three players on the WTA singles rankings at the Olympics have all bowed out of the quadrennial showpiece. While Australia's world No. 1 Ashleigh Barty had lost to Sara Sorribes Tormo of Spain in the opening match, No. 3 Aryna Sabalenka of Belarus fell to Croatia's Donna Vekic in the second round on Monday, and now world No. 2 Naomi has lost in the third round. With No. 4 Sofia Kenin of the US and No. 5 Bianca Andreescu of Canada not competing here, No. 6-ranked Elina Svitolina of Ukraine is now the highest-ranked player left in the draw. Marketa took a 4-0 lead with a double break and finished the opening set in 24 minutes. But Naomi looked like she was warming up for the second set when she broke in the first game of the second set and then held for a 2-0 lead. But Marketa broke back for 2-all and broke the Japanese one more time in the last game of the match to snuff out Naomi's challenge. The Czech player finished the match with just 10 unforced errors to Naomi's 32. Meanwhile, there were upsets galore in late evening matches on Monday at the Ariake Tennis Park as Spain's Paula Badosa, Belgium's Alison Van Uytvanck and Donna Vekic pf Croatia took out a trio of top-10 seeds to reach the third round at the Olympics. Paula took out No. 6 seed Iga Swiatek of Poland 6-3, 7-6(4), while Alison and Donna beat No. 10 seed Petra Kvitova of the Czech Republic and No. 3 seed Aryna Sabalenka of Belarus, respectively. Belgium's Alison came from a set down to beat world No.13 Petra, 5-7, 6-3, 6-0, by winning the last 10 games. It was the 27-year-old's first win over a top-20 player in over three years, dating back to a victory over then-defending champion Garbine Muguruza of Spain at the Wimbledon in 2018. She'll have a rematch with the Spaniard in the next round. "She's (Petra) a legend in our sport," Alison was quoted as saying by ITF. "She's an absolute great player and it's an honour to share the court with her -- that's what I told her at the net. I think what she has done for women's tennis is incredible. "I hope that I can maybe some day achieve the same things she has achieved. I'm proud of myself with what I did on court today and the level I reached." /IANS