Naomi Osaka's bid for a third tour title ended in a straight-sets semifinal defeat to Anastasija Sevastova at the China Open on Saturday.The Latvian, ranked 20th in the world, knocked off the U.S. Open champ 6-4, 6-4 in 1 hour, 31 minutes. According to the WTA website, the victory over the sixth-ranked Osaka was Sevastova's fourth over a top-10 opponent this season."You have to stay aggressive, you have to stay concentrated," Sevastova said afterward in an on-court interview. "Naomi, she's a great player, one of the best this year.""She's so confident. So you have to stay there. You have to…READ FULL ARTICLE