Karen Khachanov has completed an impressive singles campaign at the Hopman Cup with a win over Japan’s Yuichi Sugati.

The 21-year-old Russian converted five of seven break points to beat Sugati, ranked No.40, in just over an hour, 6-4 6-2.

Khachanov is ranked No.45, but has had an impressive start to the year with far from disgraceful losses to top 10 players Roger Federer and Jack Sock in the mixed-team’s round robin event.

His win also means Japan and Russia will play a live fast4 mixed doubles match later on Thursday to determine who finishes last in Group B.

The USA and Switzerland will do battle on Thursday night for a place in Saturday’s final.

Earlier, Japan’s Naomi Osaka pushed through illness to claim a thrilling upset victory over world No.15 Anastasia Pavlyuchenkova in the women’s singles.

After not being able to play at all against the USA on Tuesday, Osaka, ranked 68, required assistance from the doctor during the second set against the Russian, but continued under duress to claim a 6-4 3-6 7-6(5) victory.

Osaka claimed all 15 points when she landed her first serve during the opening set, assisted by four aces.

But she could hardly cover the court in the second set and at times in the third.

However, she managed to hit enough winners in a see-sawing final set to see her through.

She looked to be cruising to an easy tiebreak victory when leading 4-0, but couldn’t keep concentration then either and quickly found herself in a battle at 5-5.

Pavlyuchenkova struggled to win points on her own serve, even when she did get her first attempt in.

After forfeiting against the USA and losing in straight sets to Switzerland’s Belinda Bencic, Osaka was happy to not only get on the court, but notch up a win.

“I have been really nervous to play here, especially the first night against Federer and Belinda (Bencic) but it’s been an experience,” she said.

“I am really happy I could play somewhat well in the last match.

“I just feel like to play like that against someone so well and not be 100 per cent and still win I should be proud of myself.”

Pavlyuchenkova leaves Perth without a singles victory.

The 2017 Australian Open quarter-finalist also lost to Bencic and the USA’s CoCo Vandeweghe during the tournament.