PERTH  - Australian captain Michael Clarke's inspired start to 2012 continued when he led his side to victory over Sri Lanka in their tri-series one-day international at the WACA Ground on Friday.

Man of the match Clarke had an impact with both bat and ball as Australia won by five runs to remain unbeaten after two outings in the triangular tournament. Australia made 231 from 49.1 overs and in reply Sri Lanka was dismissed for 226 from 49.5 overs, after a last-wicket stand almost snatched an unlikely win for the tourists.

The Sri Lankans appeared to do a good job with the ball after captain Mahela Jayawardene won the toss and elected to field, Clarke top scoring with a polished 57. Some superb fielding helped the Sri Lankan cause, with a couple of fine catches, highlighted by Nuwan Kulasekara's brilliantly athletic caught and bowled to remove the dangerous Michael Hussey for 23.

However, last year's beaten World Cup finalists were not as effective with the bat and looked headed for certain defeat at 180 for nine, still needing 51 to win.

But Angelo Mathews and Dhammika Prasad put on 46 for the last wicket to threaten to snatch an incredible win.

The pair needed 18 to win from the final over and Mathews hit the first two Mitchell Starc deliveries for four and six to narrow the equation to eight from four balls.

Two singles left them chasing six from the last two balls, but Mathews (64) holed out to Daniel Christian on the long on boundary from the penultimate ball to hand the relieved Australians a thrilling victory.

The Sri Lankans earlier appeared to be cruising at 61-1, but suffered a major blow when Kumar Sangakkara was run out for 22 in an ugly mix-up with opener Tillakaratne Dilshan (40).

They found it hard to recover from the loss of their most prolific batsman and Clarke's inspired season continued when he brought himself on for a rare bowl in the 31st over.

Dinesh Chandimal was on 37 and appeared to be Sri Lanka's last real hope of victory, but he was trapped leg before wicket by Clarke's first delivery.

Australia has not lost in six matches, four Tests and two one-day internationals, this year under Clarke, their only defeat a Twenty20 loss to India under the leadership of George Bailey.

The skipper also made 626 runs at 125.20 in the recent 4-0 Test whitewash of India.

His half-century helped Australia recover from the early loss of opener Matthew Wade and Ricky Ponting, both dismissed for one as the home side started poorly to be 26-2.

Opener David Warner blasted 34 from 29 balls before being bowled by Angelo Mathews (2-37), while David Hussey (27) and Dan Christian (33) both made promising starts but weren't able to convert them into substantial totals.

The 56-run partnership between Clarke and Christian for the sixth wicket was the highest of the innings, but tailenders Clint McKay (25) and Mitchell Starc (14) added 32 ultimately valuable runs for the ninth wicket.

The next match sees India face Australia in Adelaide on Sunday.

ScoreCard

Australia:

D Warner b Mathews    34

M Wade c Kumar b Kulasekara    1

R Ponting lbw Malinga    1

M Clarke c Mahela b Mathews    57

M Hussey c & b Kulasekara    23

D Hussey c Thirimanne b Malinga    27

D Christian st Kumar b Senanayake    33

R Harris c Kulasekara b Senanayake    3

C McKay c Thirimanne b Prasad     25

M Starc c Tharanga b Prasad     14

X Doherty not out     2

EXTRAS: (lb6, w5)    11

TOTAL: (all out; 49.1 overs)    231

FOW: 1-22, 2-26, 3-50, 4-81, 5-130, 6-180, 7-190, 8-192, 9-224, 10-231.

Bowling: Malinga 10-0-48-2, Kulasekara 10-0-39-2, Mathews 9-0-37-2, Prasad 9.1-0-55-2, Senanayake 10-0-45-2, Dilshan 1-0-1-0.

Sri Lanka:

U Tharanga c Clarke b Starc    5

T Dilshan c Wade b Harris    40

K Sangakkara run out    22

D Chandimal lbw Clarke    37

M Jayawardene c Wade b Christian    13

L Thirimanne b Doherty    3

A Mathews c Christian b Starc    64

N Kulasekara c Wade b Christian    8

S Senanayake st Wade b Doherty    9

L Malinga c Wade b McKay    1

U Tharanga not out    15

Extras: (lb3, w6)    9

Total: (all out; 49.5 overs)    226

FOW: 1-11, 2-61, 3-88, 4-110, 5-119, 6-129, 7-143, 8-175, 9-180, 10-226

Bowling: Harris 10-0-43-1, Starc 9.5-0-50-2 (2w), McKay 10-0-50-1 (2w), Christian 8-1-47-2 (2w), Doherty 10-0-24-2, Clarke 2-0-9-1.