Openers David Warner and Mitchell Marsh hit swashbuckling hundreds against a sloppy Pakistan to lift Australia to 367-9 in their World Cup clash in Bengaluru on Friday.

Warner survived a leg-before appeal off the very first ball of the match and was then dropped on 10 in the fifth over, before cracking a punishing 124-ball 163 after Australia were sent in to bat on a flat Chinnaswamy Stadium pitch.

Marsh, celebrating his 32nd birthday, clobbered a 108-ball 121 as the pair raced to an Australian World Cup opening stand record of 259 by the 34th over, much to the delight of a 30,000 crowd.

Pakistan's successful 345-run chase against Sri Lanka in Hyderabad 10 days ago is the highest in World Cup history.

Their highest ODI chase was also against Australia, 349 in Lahore last year.

Warner's innings had 14 boundaries and nine towering sixes as he and Marsh spared none of the Pakistan bowlers. Marsh's knock was spiced with ten boundaries and nine sixes.

Their stand -- just 23 short of the World Cup opening record of 282 by Sri Lanka's Upul Tharanga and Tillakaratne Dilshan against Zimbabwe at Pallekele in 2011 -- was helped by some poor Pakistan bowling and fielding.

It was the innings-turning moment when Warner's miscued shot off Shaheen Shah Afridi ballooned in the air, but Usama Mir -- replacing Shadab Khan in the side -- let the ball slip between shaking hands.

Warner made the most of his reprieve as he and Marsh hit four boundaries and a six off pacer Haris Rauf's first over, taking 24 in all.

Australia smashed 82 in the first power-play and completed 200 in the 30th over.

Warner completed his second World Cup century -- and 21st overall -- with a single off spinner Mohammad Nawaz off 85 balls while Marsh reached his second ODI hundred with a six in the same over, taking 100 balls.

Ironically, it was Mir who caught Marsh off Shaheen to break the stand in the 34th over.

Glenn Maxwell, sent in at three to keep up the momentum, fell first ball, caught by Babar Azam off Shaheen while Steve Smith was caught and bowled by Mir for seven.

Warner continued the carnage with three more sixes before falling to Rauf, holing out at long-on.

Australia's previous highest World Cup opening stand was 183 set by Brad Haddin and Shane Watson against Canada at this same venue in 2011.

Shaheen, who finished with 5-54, helped Pakistan come back in the last ten overs with six wickets falling for 70 runs. Rauf took 3-83.

Brief Scores: Australia 367-9 in 50 overs (D. Warner 163, M. Marsh 121; Shaheen Shah Afridi 5-54)