Sportsmanship isn't always a word you associate with matches involving Nick Kyrgios — but that's exactly what we got when one of the Australian Open's most enthralling matches was over.

Grigor Dimitrov toppled the Australian 7-6 7-6 4-6 7-6 in three hours and 26 minutes in an encounter that won't soon be forgotten by the crowd at Rod Laver Arena nor those who watched on TV.

The two young guns showed there is a future beyond Roger Federer, Rafael Nadal and Co. as they went blow for blow in a contest worthy of being a grand slam final as opposed to the fourth round clash it was.

Kyrgios hit hard at every opportunity and Dimitrov withstood the barrage while displaying tremendous court coverage. He stood up in clutch moments during the three tiebreakers and showed enough to suggest this could well be the tournament where he breaks his major title duck.

Bulgaria's Grigor Dimitrov celebrates after defeating Australia's Nick Kyrgios. Photo / AP
Bulgaria's Grigor Dimitrov celebrates after defeating Australia's Nick Kyrgios. Photo / AP

Those in the stands knew they had witnessed something special and so too did the players. After Dimitrov smoked an incredible cross-court passing shot on the run off his forehand wing to seal the match, the pair came together and shared a long embrace at the net.

Kyrgios told the Bulgarian to "believe" before the victor delivered a passionate message of his own.

Tough battle out there against my good friend Grigor Dimitrov. Couldn’t get the win tonight, but thank you all for the...

Posted by Nick Kyrgios on Sunday, 21 January 2018

Aussie tennis legends Todd Woodbridge and Lleyton Hewitt noted how special the moment was.

"That handshake and that moment at the net — great significance in the career of Kyrgios, one thinks," Woodbridge said.

"It was respect by both players shown at the net," Hewitt added. "I know for a fact they have amazing respect for each other out there, both on and off the tennis court.

"The way that these two champions went about it tonight, what a match we have seen in the round of 16 here at the Australian Open."

"Playing against Nick is always tricky," Dimitrov told the Seven Network.

"Two weeks ago I lost against him ... he was serving unbelievable, playing unbelievable and competing.

"He deserves a lot of credit ... he fought really hard.

"Even when I was serving for the match I just felt it was still not over. I was still not finding my spots well and again he was playing very well.

"But I'm glad to go through the match (and win it)."

The No.3 seed will face unseeded surprise packet Kyle Edmund in the quarter- finals after the Briton defeated Italian Andreas Seppi in four sets.