'Don't understand tennis': Rafael Nadal slams 'disrespectful' ATP Cup crowd

Novak Djokovic has confirmed his hot favouritism for an unprecedented eighth Australian Open crown after inspiring Serbia to a historic victory over Spain in the inaugural $22 million ATP Cup final, sparking scenes of ecstasy inside Ken Rosewall Arena.

Djokovic extended his hardcourt mastery over Rafael Nadal with an ominous 6-2 7-6 (7-4) win over the world No.1 before teaming with Victor Troicki to take the deciding doubles rubber 6-3 6-4 over Feliciano Lopez and Pablo Carreno Busta.

‘NEED TO FIX IT’: Nadal hits out at organisers after loss in ATP Cup final

Serbia's stirring fightback, after Roberto Bautista Agut had put Spain 1-0 up in the best-of-three tie with a 7-5 6-1 win over Dusan Lajovic in Sunday night's opening match, left Djokovic's army of red, white and blue followers in the stadium overjoyed.

"Novak, Novak, Novak," they chanted after their hero rallied from a service break down in the opening set of the doubles to reel off six successive games to seize command of the final.

While Nadal pulled out of the doubles, saying he was low on energy after a total of eight singles and doubles matches in nine days, there was no stopping Djokovic despite the world No.2 carrying Serbia with a similar twin workload.

Appearing for the first time in Sydney in a decade, the 16-times grand slam champion said he'd never played in such an atmosphere as he had in front of fervent Serbian fans over the past three days.

"Off the charts," Djokovic said.

"I have never experienced such a support in my matches ever anywhere, and I have played the biggest stadiums in tennis, and this was something different.

"I'll remember this experience for the rest of my life."

Even Nadal, one of the most popular athletes on the planet, found the going too much, complaining to the chair umpire and then giving Serbian spectators a sarcastic thumbs up after dropping serve to fall 5-2 behind in the opening set.

"Honestly, the crowd was fantastic every single day but sometimes people from some countries, they probably don't understand how the tennis goes," Nadal said.

"They think it's about football or this stuff and atmosphere in tennis is different, no?

"The respect for the players should be there, and at some point I think the respect with small part of the crowd have been not there."

Djokovic continues insane streak over Nadal

Djokovic's ninth consecutive hardcourt win over Nadal reaffirmed the world No.2 as once again the man to beat at the season-opening Melbourne major starting on Monday week.

The super Serb has won 19 straight sets against Nadal on cement since last losing to his great rival in the 2013 US Open final.

"I started off the match perfectly - everything worked for me," Djokovic said.

"My serve got me out of trouble in the second set. I'm just really glad to hold my nerves again."

His latest triumph completed a perfect preparation for the season-opening slam starting on Monday week, following earlier victories at the $22 million event over US Open finalists Daniil Medvedev and Kevin Anderson, Gael Monfils, Christian Garin and Denis Shapovalov.