The 19-year-old Canberran  beat Italian Andreas Seppi to become the youngest Australian Open men's quarter-finalist in almost a quarter of a century and the first local to reach the final eight since Lleyton Hewitt a decade ago.

But his on-court attitude has drawn the ire of social media users, particularly after he swore at members of the crowd, including one person using their mobile phone.

"Get off your f---ing phone," he yelled, during the crucial fourth set.

Kyrgios has already been fined $4926 for racquet abuse and audible obscenities during his first-round match last Monday.

He could be fined again because his expletive outburst was heard by television viewers.

His temper boiled over at the end of the second set when he slammed his racquet into the ground, nearly breaking it in two.

But Kyrgios, who has become the poster boy of the Australian Open, recovered to defeat Seppi 5-7, 4-6, 6-3, 7-6 (7-5), 8-6 in three hours and 34 minutes, with a new racquet in hand.

Despite his stellar comeback, many were unimpressed with his attitude.

"I know there's a lot of pressure, but screaming at the ball boys / girls for your towel isn't cool," @Waverley73 tweeted.

I know there's a lot of pressure but screaming at the ball boys / girls for your towel isn't cool #AusOpen #Kyrgios — Glen (@Waverley73) January 25, 2015

"Just once I wish Australians would see people as assholes even when they have won. It seems winning excuses disgusting behaviour," Rachel Smith tweeted.

However, inside Hisense Arena the rapturous crowd was forgiving of Kyrgios.

Throughout the night, roars from the Kyrgios match could easily be heard inside neighbouring Rod Laver Arena. There was even a brief delay during the Andy Murray - Grigor Dimitrov game when the Kyrgios crowd erupted into applause after the Australian prevailed.

The 19-year-old did not please everyone in the arena. Three fans tried to leave early only to have Kyrgios turn around and ask: "Oi! Where are you going?"

The humiliated trio immediately sat back down as the crowd started booing.

Yet some criticised the "blind nationalism" on display on the eve of Australia Day.

"#Kyrgios embarrassing our country on the eve of our national day. Show some dignity & respect. No one is proud of your attitude," @applaudlife tweeted.

David Lees wrote: "#Kyrgios has a LOT of growing up to do. And if the crowd's blind nationalism keeps up, he may never. An embarrassment to the game. #ausopen"

#Kyrgios has a LOT of growing up to do. And if the crowd's blind nationalism keeps up, he may never. An embarrassment to the game. #ausopen — David Lees (@davdlees) January 25, 2015

Kyrgios will face sixth seed Murray in the quarter-final, with some predicting more tantrums will be on display when the two highly emotional players meet.

Tuesday Night #Kyrgios vs #Murray . So many names for this match up come to mind. The Battletude,War of Whingers,The Complainers Crusade.... — Lukas Vandenbergh (@lukasvdb10) January 25, 2015

#Kyrgios and #Murray to go head to head. On that note, it'll be interesting to see who throws the bigger tantrum. #AusOpen #tantrumtennis — Natalie Aoun (@spoonofaoun) January 25, 2015

If #Kyrgios can learn to turn his passionate aggression into something constructive he'll be unstoppable!! Still <3 him despite it #AusOpen — Julia Eppingstall (@Julzmusic) January 25, 2015

This #Kyrgios kid is fun to watch but holy shit he's a psycho.... @AustralianOpen — Wade Davidson (@Wade_davidson10) January 25, 2015

I now like #Kyrgios simply because the public do not, he is my second fav behind #tomic #notjoking #AusOpen2015 — Dominic McCarthy (@dominicmccarthy) January 25, 2015