Khawaja relishes Test ton in Karachi

"My family is actually from Karachi, this is where the Khawajas are from," he said.

"Everyone in my family is born in Karachi except me so this is my home, I have been here a lot.

"Every Test hundred is pretty special - the Sydney ones are probably up there as my favourites.

"This one, after last week getting 97, it has got to be up there ... I was born in Islamabad but my family is all from Karachi so this one meant a lot."

Only four members of his clan were in the National Stadium on Saturday but they joined the rest of the crowd in wildly cheering Khawaja's latest feat.

"They have been so supportive, I couldn't have asked for any more," he said.

"I love it because they want Pakistan to win, you can tell they're diehard Pakistani supporters, but they're very supportive of me."

Khawaja now has three tons in four Tests, and averages 119.75, since his recall in January after a 29-month absence.

And the 35-year-old is relishing a ride he never thought would come again.

"I wanted to play for Australia again but it wasn't something that was on my radar," Khawaja said.

"I know the game can change very quickly so I am just enjoying it - a lot of people say that but I am at a point in my life and my career where it's more about enjoyment than anything else.

"Nothing lasts forever, I understand that."

Khawaja combined with Steve Smith (72) in a 159-run partnership which defied some defensive bowling tactics from their hosts.

Spinners Sajid Khan and Nuaman Ali spent an hour of the final session pitching wide of leg stump in a ploy described in commentary by Pakistani great Waqar Younis as "ridiculous".

Khawaja and Smith just kept padding the ball away.

"Just give 'em nothing was our plan," Khawaja said.

The Australians have now set their sights on a massive first innings score. Just how big?

"850," Khawaja said, laughing.

"If we bat well enough tomorrow morning we will have an opportunity to drive the game.

"I felt like Pakistan were in the same position last game but they just didn't do it, they didn't really take any opportunity to increase their run rate."