Sri Lanka is staring down the barrel at 44-3 after Australia achieved its largest ever total in Asia — 654-6 declared — on day two of the first test in Galle.

Australia's Usman Khawaja struck a maiden double hundred and Josh Inglis got a century on his test debut against Sri Lanka to power the tourists to a mammoth 654 for six before they declared their first innings on day two of the opening test on Thursday.

Opener Usman Khawaja hit his first double century in test cricket to steer Australia to 475-3 by Thursday lunch on day two of the opening match against Sri Lanka.

Australia’s batters have feasted on Sri Lanka’s bowling, racking up milestones and dominance on a rain-curtailed opening day of the first test in Galle.

Travis Head will replace Sam Konstas as Usman Khawaja's opening partner in the first test against Sri Lanka at Galle on Wednesday, Australia's stand-in captain Steve Smith said on the eve of the match.

The rainy weather conditions have given Australia a selection problem for the opening test against Sri Lanka starting Wednesday, although one thing seems certain: Travis Head will open the batting

The 35-year-old, captaining the side in the absence of Pat Cummins, needed just one run in Galle to reach the milestone in Galle.

Australia skipper Steve Smith won the toss and elected to bat first in the first Test of the two-match series against Sri Lanka at the Galle International Stadium on Wednesday. Right-hand batter Josh Inglis is set to make his debut in the longest format of the game as the Baggy Greens named him in the playing XI for the first match of the series.