Australia's dominance with the bat in Sydney has given spinners Nathan Lyon and Steve O'Keefe an opportunity to "crack this game wide open" and ram home their claims for next month's series in India.

The runs are pouring for Steve Smith's revitalised team with Peter Handscomb (110) joining the party at the SCG on Wednesday with his second century in only four matches.

Since Australia hit rock bottom when all out for 85 in Hobart nearly two months ago there have been eight hundreds scored by members of this top six, seven of them now against Pakistan. Handscomb, along with Smith and David Warner, has two, with Matt Renshaw and Usman Khawaja posting one each.

On a pitch tipped to turn more as the match goes on, Smith will turn to Lyon and O'Keefe, who are destined for key roles in the subcontinent in February and March.

Standing in their way are Younis Khan (64 not out) and ironman opener Azhar Ali (58 not out), who on day two became Pakistan's most successful batsman in a three-Test series in Australia as the tourists moved to at 2-126 in their first innings.

They frustrated Australia's drive towards a 3-0 clean sweep and given how accomplished they are against spin they pose what may be an instructive challenge for Lyon and O'Keefe, given what is on the horizon. In a matter of weeks it will be Virat Kohli and co at the other end.

"We just need to come out tomorrow and keep that pressure on," Handscomb said. "It's going to be a real tough grind, that wicket is pretty good. Hopefully a few footmarks start to appear and our spinners can come into it and crack this game wide open."

"I think it's going to be a challenge but both of those bowlers love a challenge. Playing against them I know how hard they work at getting batters out. They've definitely got plans when the wicket does start to deteriorate hopefully. But if it doesn't they will add their own plans. They know they will have to bowl a lot of overs, too, so I think they're looking forward to it."

Having had Josh Hazlewood reduce Pakistan to 2-6, Australia might have already had Azhar and Younis out as well if not for a series of missed opportunities on the second afternoon.

While Warner chalked up his place in the history books on Tuesday with his breathtaking century before lunch, he had a less happy day in the field on Wednesday, missing two run out chances and dropping a catch in the penultimate over of the day.

Pakistan still trail by 412 but had Warner managed to throw down the stumps on either, or both, of the occasions he had a lash in the afternoon, with first Azhar and later Younis stranded at the non-striker's end, their predicament would have been more dire.

Azhar was then spared again on 51 when Warner, stationed at leg gully, thrust out his right hand but couldn't hold a very tough chance off the bowling of Lyon.

Despite that, Australia's first innings total of 8-538 (dec) ensures them a stranglehold on the match and their bid for a whitewash wasn't harmed by more flaws in Pakistan's fielding, including two lives given to debutant Hilton Cartwright (37). Bill Lawry, on the Channel 9 commentary, concluded that they "couldn't' catch a cold in the middle of winter".

Pakistan coach Mickey Arthur described his team's fielding as "very, very frustrating".

"We can't work any harder at our fielding," Arthur said. "We catch balls continuously, [fielding coach] Steve Rixon works the guys hard, so fielding has been a massive frustration for us."

Arthur said Warner had taken the game away from Pakistan from the first over of the match, but heaped praise on Azhar and Younis for their resolve.

"At 2-6 we were in some serious strife, but to see the resilience and character and intent that has been shown by Younis and Azhar is a real example to the rest of the dressing room," he said.

Spinner Yasir Shah has a hamstring strain but Arthur expects him to bowl if Australia bat again.