Australia moved to the top of the World Cup group table as heroics from Aaron Finch and Mitchell Starc secured an 87-run win over Sri Lanka.
Finch's 153 off 132 balls helped pile on 334-7 at The Oval, with Steve Smith adding 73.
Sri Lanka got off to a flying start as captain Dimuth Karunaratne made 97 and Kusal Perera 52.
But Starc's 4-55 and 3-47 from Kane Richardson ripped out their middle order to leave them 247 all out.
A fourth win from five games moves Australia a point clear of New Zealand at the top of the table - a position they may retain until their next game on Thursday.
Despite having now beaten Afghanistan, West Indies, Pakistan and Sri Lanka, they have had their concerns on both the batting and bowling front.
Starc's figures took his tournament wicket tally to 13 and proved equally as vital as his closing-over spells against both West Indies and Pakistan.
Australia, whose only defeat so far came against India, next face Bangladesh at Trent Bridge on Thursday knowing another win could see them put one foot in the last four.
Sri Lanka's second defeat from five games, having had their past two fixtures abandoned without a ball being bowled, leaves their quest for a semi-final place in the balance.
They next face hosts England at Headingley on Friday.Finch's fireworks lead the way
Captain Finch led from the front for Australia and showed no fear about having to bat first under cloudy skies and a stiff breeze.
He got off the mark first ball with a brilliantly-timed back-foot cover drive for four and reached his century 96 balls later with his fourth six, clearing the long-off rope.
The opener's 14th ODI ton and his second in a World Cup fixture would see him go on to reach 150 off just 128 balls as he crashed the last of his 15 fours with a one-bounce pull shot over mid-wicket.
But just as he seemed to be winding up for a big onslaught in the closing overs and the chance to join an exclusive club of those to score 200 in an ODI, he fell for a career-best-equalling 153 from 132 balls.
It moved him comfortably clear as the competition's leading run-scorer and level with England's Jason Roy for the highest individual score.
That was helped in large part by a third-wicket partnership of 173 off 124 balls with Steve Smith (73), who himself registered his third half-century of this World Cup.
While Australia's innings arguably lost some momentum in the closing overs with a flurry of middle-order wickets going down, Glenn Maxwell's unbeaten 46 off 25 balls took them to 334-7.Starc bails out blunt bowlers again
Finch's 153 and Starc's 4-55 once again demonstrated both the individual brilliance and the fragility of this Australia side.
As Sri Lanka's openers plundered the best opening powerplay of the tournament to date with 87-0 in their first 10 overs, a shock win looked on the cards.
But cometh the hour cometh the man - Starc once again striking the decisive blows, just as he did when Pakistan threatened to chase down 308 in Australia's last match.
Finch had found himself having to initially juggle his four seam bowlers of Starc, Richardson, Pat Cummins and Jason Behrendorff as none could find the necessary control.
But when Starc returned for a second spell, the breakthroughs came.
Kusal Perera (52) was the first to fall to bring to an end the promising opening stand of 115 from 93 balls.
In between, the unlikely fifth bowling option of Maxwell returned a relatively economical 10 overs costing just 46 runs.
That pressure teed things up for Starc's third and decisive spell.
Sri Lanka went from being an outside chance at 209-4 in the 37th over to no-hopers at 222-7 just 11 balls later as Starc took all three of those wickets to effectively settle the contest.'Starc is world-class' - what they said
Australia captain Aaron Finch, whose side don't play again until Thursday: "We're happy with where we're sitting, but it's definitely a chance to see where we can improve and how we can work towards being on that balcony at Lord's on 14 July."
On his own form: "I think any time you manage to get a few runs, you feel pretty good about your game.
"I've been working on a few things with my technique and sometimes you don't get immediate rewards so it's nice to get some positive reinforcement from the game.
"(Assistant coach) Ricky Ponting's been brilliant to work with. It's been great to have Ricky around, no doubt."
Sri Lanka captain Dimuth Karunaratne: "It was a pretty good wicket and I thought there would be some seam movement but there wasn't much. We bowled really well in the first 25 overs but Finch and Smith batted really well in that period and after that we battled back well.
"We got a good start with the bat but our middle order couldn't capitalise on that. Starc and Cummins are world-class bowlers, and we need to come up with a plan about what we can do in that period.
"We need to win a couple of games against the top sides to make the top four."