Usman Khawaja did his World Cup prospects no harm as Australia overpowered Sri Lanka by five wickets in a warm-up match at Southampton on Monday.

Khawaja, who appears to be vying for a place at number three with Shaun Marsh, made 89 in a total of 241 for five.

The world champions rested opener David Warner (leg soreness) while former Australia skipper Steve Smith, also returning to the international scene following a year-long ban for his part in a ball-tampering scandal, batted in the nets.

Australia appear to have a settled opening combination in captain Aaron Finch and Warner.

But Warner’s absence saw Khawaja open against Sri Lanka.

“I wasn't thinking about securing an opening berth, we've looked to be clinical and not take it lightly,” said Khawaja.

“We've won three warm-ups here, and it was more about us continuing the winning ways in Dubai and India.”

Australia's latest win followed previous warm-up successes against the West Indies and World Cup hosts England that built on an encouraging 3-2 series win in India.

“Behind the scenes we've put in a lot of hard work, you need that to be able to compete at this level,” said Khawaja.

“Everyone has put in a lot of effort. We had India over in our place for a series and while we lost, that was a big turning point for us.”

He added: “They're one of the best sides and we gave them a run for their money. Then we went to India, lost the first two matches and went on to win the series. We always had the confidence we could do that.

“Winning is a habit, we say that a lot among the team. We want to keep that going, we might have lost that before, but we might have found that again heading into the World Cup.

“This time last year there was a lot of talk about our batting, everyone has their different plans -- it's just about winning games and we're managing to do that,” he explained.

Australia, who begin the defence of their title against outsiders Afghanistan in Bristol on Saturday, saw fast bowlers Mitchell Starc and Pat Cummins get in the groove as they restricted Sri Lanka to a meagre 239 for eight.

For Sri Lanka, only Lahiru Thirimanne went past fifty.

“We did not bat very well,” said Sri Lanka's Kusal Mendis.

“There was a chance to get to 300 out there on that wicket but we struggled in the middle overs and lost any momentum.

“It was a battle and it ruined the plan we had as a team. We did our best from there but we did not score enough runs and they were able to knock them off.”

But Mendis forecast Sri Lanka would find their form in time for their opening match against New Zealand

“We are confident we can turn this around,” he said.

“Angelo Mathews and Lasith Malinga will step it up at the weekend and that will give everyone a lift with bat and ball,” Mendis insisted.