Sri Lanka threw India's prospects of a berth in the tri-series finals into jeopardy with a thrilling three-wicket victory over Australia that pushed them to the top of the points table, in Hobart, on Friday.
Chasing Australia's 280 for 6, built around Peter Forrest's maiden ODI century, the islanders overhauled the target with four balls to spare in a match that went down the wire.
Sri Lanka are atop the table with 15 points from six games, one more than second-placed Australia.
Friday's victory, the islanders' third on the trot in the tournament, left India (10 points from six matches) with the arduous task of winning both the remaining matches to make it to the finals.
All the three teams have two games to go and all have a chance to make it to the finals.
If India win both the matches, Sri Lanka and Australia will be fighting for the other spot in the final.
The highlight of Sri Lanka's victory was a classy 85 off 81 balls by captain Mahela Jayawardene and a solid 80 off 100 by Dinesh Chandimal. The duo shared a crucial 63-run partnership in 12.3 overs for the third wicket to lay the foundation for victory.
Down the order, and coming out at number eight, Thisara Perera played a cameo of 21 not out from just 11 balls to take Sri Lanka home at the Bellerive Oval here. He hit a boundary and a six in the penultimate over off Daniel Christian to tilt the balance in Sri Lanka's favour.
Chandimal, on the other hand, anchored the Sri Lankan innings after Jayawardene's dismissal with a 49-run stand for the fourth wicket with Lahiru Thirimanne from 10.3 overs to take the islanders to the threshold of victory.
After Chandimal's departure in the 45th over, Sri Lanka looked like losing the plot towards the close following the quick dismissals of Farveez Maharoof (5) and Angelo Mathews (2) but Perera struck a four and a six off consecutive balls in the penultimate over bowled by Daniel Christian to seal the match.
Earlier,Forrest rallied the home side after a disastrous start. His first ODI hundred came in only his fourth match, having taken Ricky Ponting's place in the Australian batting line-up at number three.
In his previous three tri-series matches, Forrest had batted at number four and hit two half-centuries.
Forrest scored 104 runs, the first century of the tri-series, and with Clarke mustered a 154-run partnership for the third wicket after the hosts had lost both the openers.
Matthew Wade (5) and David Warner (7) were cooling their heels back in the pavilion after Australia opted to bat at the Bellerive Oval.
Forrest and Clarke then combined forces to negate the early advantage that Sri Lanka gained through the pace duo of Nuwan Kulasekara and Farveez Mahroof.
Kulasekara drew first blood by having Wade caught by Jayawardene off his fifth ball of the innings while Mahroof had Warner caught behind.
Forrest, who had started his ODI career with a 66 against India at Adelaide, hit 10 fours and two sixes.
He completed his century in the 40th over when he took a single of Thisara Perera, but was out two balls later after ballooning a catch to Angelo Matthews at deep extra cover.
Matthews had dismissed a well-set Clarke in his previous over and two quick strikes brought Sri Lanka back in the match.
Clarke's 72 came off 79 balls, inclusive of seven boundaries and two sixes.
However, Sri Lanka did not get any respite, as Mike Hussey (21), his brother David (40 not out) and Brett Lee (20 not out) played handy cameos to get Australia to a very challenging total.
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