Reigning women's singles champion Akane Yamaguchi kept her title defense on track with a 21-17, 21-17 victory over fifth-seeded Spaniard Carolina Marin in the quarterfinals of badminton's BWF World Championships on Friday.The Japanese top seed took control of the first game at Tokyo Metropolitan Gymnasium by winning six straight points from 13-12.She held off a determined Marin in the second game, clinching three consecutive points to close out the match in front of the home crowd against the three-time world champion and 2016 Olympic gold medalist."The second game didn't develop at the kin…READ FULL ARTICLE