NOTTINGHAM: It's safe to say David Warner has found his feet.

In the sixth match of Australia's Cricket World Cup campaign, and six matches into Warner's official comeback from a 12-month suspension, he showed off both sides of his personality in hitting a tournament-high 166 which Bangladesh was too resigned to challenge on Thursday at Trent Bridge.

The result was a 48-run win which strengthened Australia's semifinal credentials and punctured Bangladesh's.

Warner led Australia to 381-5, its second highest World Cup total, and Bangladesh replied with its highest one-day international score of 333-8, including a maiden World Cup hundred for Mushfiqur Rahim. But the unbeaten 102 was window dressing to a tame ending. The contest petered out long before then, and hundreds of Bangladesh fans had already left Trent Bridge.

"Too much, 381," Bangladesh captain Mashrafe Mortaza conceded.

Australia, the defending champion back on top of the standings, goes to Lord's on Tuesday to face top-ranked England in good shape. Bowling allrounder Marcus Stoinis and Nathan Coulter-Nile recovered from injuries and took two wickets each. Since its only loss to India, Australia has won three straight group matches, and posted four consecutive 300-plus totals.

For Bangladesh, defeat means it has to win its last three matches against Afghanistan, mighty India, and Pakistan to make its first World Cup semifinals. Not impossible, but the top four of Australia, New Zealand, England and India looks increasingly set with more than two weeks left of the group stage.

"It's going to be difficult for sure (to make the semis)," Mashrafe said, "even if we win all those three matches."

Warner is atop the tournament's run-scorers list with 447, and matched only by captain Aaron Finch in scoring four fifties. The difference is, Warner has two centuries and Finch one.

His latest outing showed off the old and new David Warner. The new Warner, desperate to succeed after his suspension from the ball-tampering affair, began cautiously again on a soft pitch, soaking up dot balls to try and bat deeper, and hitting to fielders. Two weeks ago at Trent Bridge he made 3 against the West Indies. He gave Bangladesh a chance on 10 but Sabbir Rahman let it pass through his hands.

"It's generally not my game to stick there, I usually try and go after it a little bit, come down the wicket or something," Warner said. "Must be a bit more maturity, I think."

Warner saw enough bad balls to hang with Finch. They shared a stand of 121 in 21 overs. He and Finch have been together for 519 runs at this World Cup, easily the best of any opening partners, and a far cry from the 2015 World Cup when their best stand was 57. And Australia still won that one.

The skipper, out for 53, was apparently annoyed that he was replaced by Usman Khawaja and not bigger hitters Steve Smith or Glenn Maxwell. The issue became valid as Warner and Khawaja strolled to 40 overs. But that's when old David Warner came out, the one who can blast any attack. Khawaja also came out of his shell. Together with Maxwell, they smashed 102 runs in 6.1 overs.

Warner became the first batsman to score 150-plus twice in World Cups. His 16th ODI hundred came off 110 balls. He added 66 more runs off 37 balls.

He and Khawaja combined for 192, marking the first time Australia has had two century partnership at a World Cup.

Maxwell added a 10-ball 32 then was run out and Khawaja departed two balls later for 89 off 72.

The top three all fell to part-time medium-pacer Soumya Sarkar, who had only one wicket previously in ODIs.

Australia was 352-2 in the 47th over and threatened 400, but a messy end, including a half-hour rain delay, concluded on 381-5.

"I felt a little bit bogged down and frustrated, I kept hitting fielders but I managed to hang in there," Warner said.

"You always keep wickets in hand, especially in one-day cricket ... you have to respect the new ball and the bowlers bowled well. You've got to adapt and it's about momentum, so far things are working well. It was a tad slow the wicket, but it was a grind for the bowlers."

But Australia's attack has enough depth and variety to defend 381, and prey on batsmen under pressure to score. They made Bangladesh's chase stutter out of the gate.

Soumya was stranded by Tamim and run out on 10 by Finch in the fourth over.

Shakib arrived and looked good to become the first Bangladeshi to hit six successive fifties in ODIs. But on 41 off 41 balls he mistimed a slower ball from medium-pacer Stoinis and gave up an easy catch in the 19th over. The crowd fell silent as it absorbed the massive blow to Bangladesh's hopes.

Australia celebrated the significance of the wicket by smothering Stoinis, back after missing two games with a left side strain, in multiple hair rubbings.

Tamim had to go big, and the team's best batsman hit his first half-century of this World Cup. Then on 62 he chopped on, giving Starc a tournament-leading 14th wicket. The run rate required was almost up to 10.

Starc bounced the next ball off Liton Das' helmet, and Liton lasted five more overs, out for 20.

Mushfiqur Rahim and Mahmudullah, with a dozen years together in the national team, dug in and enjoyed the sun-baking pitch at run-a-ball pace. They had Bangladesh tracking almost similarly with Australia, but without wickets in hand.

Mahmudullah tried to push on but he holed out on 69 off 50 balls, and Sabbir Rahman chopped the next ball from Coulter-Nile on to his stumps. The high-spirited Bangladesh fans took the cue to leave, and missed Mushfiqur becoming the third Bangladeshi to score a hundred in World Cups after Mahmudullah and Shakib. It was merely a consolation.