PERTH, Australia — Youngster Naomi Osaka showed why she is regarded as a star of the future with a brave victory over Anastasia Pavlyuchenkova as Russia beat Japan 2-1 at the mixed teams Hopman Cup in Perth on Thursday. Osaka, ranked 68th in the world, withdrew from her previous match due to illness and appeared to be struggling physically at various times during the match, but still managed to edge past the world No. 15. Both sides were already out of finals contention and Russian Karen Khachanov then squared the Group B tie with a comfortable win over Yuichi Sugita in the men's singles. The Russians then secured their first win of the tournament with a decisive victory in the mixed doubles. The match between Osaka and Pavlyuchenkova featured a host of momentum changes as the form of both players ebbed and flowed, and the Japanese woman struggled with her health. Osaka started confidently and took the first set, but she required medical attention while leading 3-2 early in the second set. The 20-year-old, who was named the WTA Newcomer of the Year in 2016 and has been ranked as high as 40th, appeared distressed and dropped the next four games as the Russian leveled the match. Osaka seemed to be fading, but then came out and broke Pavlyuchenkova's serve early in the third, only for the Russian to break back in the fourth game. The set went to a tie-breaker and Osaka surged to a 4-0 lead, but then dropped the next five points in succession. However, she again dug deep and earned her first match point, crunching a forehand winner down the line to secure a hard-earned 6-4, 3-6, 7-6 (7/5) win. She was pleased to be able to eke out the victory given the circumstances. Ranked 45th in the world, Khachanov finally notched his first singles win of the week. After losses to top 10 duo Roger Federer and Jack Sock in his previous singles outings, the towering Khachanov was dominant against Sugita, breaking the Japanese player's serve five times. The Russian were far too good in the Fast4 mixed doubles, winning 4-1, 4-0. Belgium beat Australia Elise Mertens fended off Daria Gavrilova while David Goffin blitzed his way past Thanasi Kokkinakis as Belgium secured a 3-0 victory over Australia in the Hopman Cup on Wednesday. Mertens fought back from a set down to outlast Gavrilova 2-6, 6-4, 6-2, in a two-hour battle at the Perth Arena to help Belgium keep their hopes of reaching Saturday's final alive. Gavrilova broke Mertens early in the match and clinched the opening set with ease. She continued to attack her rival in the second set but world number 36 Mertens saved a break point and changed her gameplan to counter the Australian. Mertens reeled off three games in a row to level the contest at one set all and used the momentum to prevail in the decider. Goffin, who beat world No. 4 Alexander Zverev in his opening match, struck 27 winners in his 6-4, 6-2 victory over Kokkinakis to clinch the tie. Belgium then won the mixed doubles dead rubber. Belgium can reach the final if they beat Canada in their next match and Australia fail to better their result against Germany. — Agencies