Canberra - Australia zeroed in on a 2-0 series win after dismissing Sri Lanka for 215 on Sunday then piling on more runs to leave the visitors with a mountain to climb to stay in the second Test at Canberra.
Sri Lanka resumed the third day at 123 for three on what appeared to be a decent batting track, but in a hostile morning session lost four wickets and Kusal Perera, who retired after being hit on the head by a bouncer.
Their resistance finally folded in the second over after lunch, with Mitchell Starc taking five wickets to leave them trailing by 319 after Australia's first innings 534 for five declared.
By tea, the hosts' lead had been extended to 386 with Usman Khawaja not out 25 and Travis Head on 14 after skipper Tim Paine opted not to enforce the follow-on.
But it was far from plain sailing for Australia, who were 67 for three at the break.
Marcus Harris again failed, out for 14 with Kusal Mendis taking a superb diving catch at slip off Kasun Rajitha, throwing his place on the Ashes tour to England later this year into question.
Mendis held another catch to dismiss first innings century-maker Joe Burns for nine, this time off Vishwa Fernando, and Rajitha struck again to remove Marnus Labuschagne for four.
In an incident-packed morning at Manuka Oval, Paine handed the ball first up to Jhye Richardson and Pat Cummins and they responded with a slew of bouncers.
Both Perera, who resumed on 11, and Dhananjaya de Silva, on one overnight, took blows to the head in the opening two overs, but were fine to continue.
Perera was then hit flush on the helmet ducking into a Richardson ball on 27.
The neck protector flew off and a Sri Lankan physio rushed to his aid. He continued and added two more runs only to call the physio again four balls later.
Once again he opted to bat on but was clearly feeling the effects and was helped off the field soon after. He stayed at the ground monitored by medics, but did not play again.
Ironically, the courageous Dimuth Karunaratne replaced him after being declared fit again after being felled by a brutal bouncer on Saturday from Cummins.
He had laid prone on the ground for at least 10 minutes before being stretchered off in a neck brace, but after a hospital check was cleared of concussion and given the OK to resume his innings.
The opener returned on 46 and smacked a four to bring up his 22nd Test 50 before being caught at gully by Kurtis Patterson off Starc after adding nine more.
He was out just three balls after de Silva bizarrely hit his own wicket while attempting a pull shot off Starc. As his bat swung around it took one of the bails off and he was gone for 25.
In the next over debutant Chamika Karunaratne also fell, without scoring, getting an edge to a Nathan Lyon ball with Starc holding the catch at slip.
Niroshan Dickwella was out lbw to Labuschagne on the last delivery before lunch, and when they returned Dilruwan Perera and Fernando lasted just eight more balls.
Starc did the damage with 5-54, silencing his critics after a lean spell.
Australia won the first Test in Brisbane by an innings and 40 runs.