'One an inspiration, the other an embarrassment'

At exactly the same time as Nick Kyrgios was disgracing himself in Shanghai, Tim Cahill was showing why he's one of Australia's most-loved athletes.

Kyrgios is facing the prospect of another season-ending ban after branding an official "a joke" before sensationally quitting his first-round match at the Shanghai Masters on Tuesday night.

BIG WHACK: Kyrgios cops punishment for Shanghai walk-off

And on the other side of the world, Socceroos great Tim Cahill was busy helping his country take one step closer to a fourth-consecutive World Cup, bagging a double to help Australia sink Syria in extra-time.

The contrast between Kyrgios and Cahill was clear for all to see, and the biggest difference boiled down to one key thing - heart.

Kyrgios blamed a stomach bug for his controversial walk-off, but TV microphones caught him complaining about the umpiring to his entourage and saying he'd quit if he lost the first set.

In complete and utter contrast, Cahill was displaying the never-say-die attitude he's renowned for, repaying the faith of coach Ange Postecoglou in a rare start for his beloved country.

Rather than give up and get down in the dumps as he sat on the bench for so many recent Socceroos games, Cahill bided his time and grabbed his opportunity when he was granted it.

Australian media icon and former Wallabies coach Alan Jones summed up the Kyrgios-Cahill dynamic in one perfect tweet.

He then blasted the young Aussie on Channel 7's Sunrise program on Wednesday morning.

"These blokes do this because they get away with it," Jones said.

"That behaviour is utterly unacceptable and the International Tennis Federation has to say 'you don't belong, you're suspended for six months and you have to make application to come back and join us."

The sentiment wasn't lost on a number of others:

Incredibly, Kyrgios's dramatic walk-off comes after the volatile star was suspended from the ATP Tour for tanking at the very same tournament in China 12 months ago.

Kyrgios failed to front media in Shanghai before releasing a statement blaming illness and a sore shoulder for his conduct, which leaves his immediate playing future in doubt once again.

Less than two months shy of his 38th birthday, Cahill defied age and reason to rescue Australia's World Cup fortunes at ANZ Stadium.

That he reached a record half-century of international goals in the process was a by-product for the team-first veteran, whose bid to play at a fourth World Cup would have bit the dust without his own heroic intervention.

"We had to win," Cahill said. "There were no more dress rehearsals.

"There's no more Thailand game where you get another chance - this was it.

"You can't go into this game without conviction and intent or you get left behind."

with AAP