Japanese player Yoshihito Nishioka left fans and experts stunned in his astounding capitulation to Karen Khachanov at the Australian Open - recording an incredibly rare 'bronze set' in his loss on Sunday.

The Russian 18th seed demolished his opponent in a straight-sets mauling of Nishioka 6-0 6-0 7-6 on John Cain Arena.

Nishioka was so outclassed in the opening two sets that he only managed 13 points in just 46 minutes.

In the second set, Nishioka only won two points in six games - which in the tennis world is a very rare occurrence called a 'bronze set'.

Tennis writer Ben Rotherberg pointed out how odd it was to see at this level of the game. 

'A bronze set! Exceedingly rare, especially in the second week of a Slam,' he wrote on twitter.

The Russian looked like he might achieve a triple bagel win over the the Japanese World No.33 - which occurs when a player wins 6-0, 6-0, 6-0 - but Nishioka finally found his form in the third set and received huge applause from the crowd.

Khachanov, who won in less than two hours, is now in the last eight at a Grand Slam for the fifth time.

The big-serving Russian remarked that he was as surprised as the fans in the lopsided first two sets of the match.

'First two sets I didn't know what was going on but it's never easy when you are going with a score too easy,' the world No.20 said.

'You feel it and then at one point Yoshi tried to turn it around, he pumped the crowd and it's normal.

'So I tried to stay focused all the match from the beginning but it's not easy to win with this score, three straight sets. So the third set was a really tough one.' 

Khachanov will next face rising American 29th seed Sebastian Korda.