London, Jun 18 (IANS): Sri Lanka edged Australia by 20 runs and in the process booked their seat in the semifinals of the Champions Trophy at the Kennington Oval here Monday.

England tied on four points with Sri Lanka top Group A, due to a better run-rate, and will play South Africa Wednesday in the first semifinal here. Sri Lanka will take on India at Cardiff in the second semifinal Thursday.

Mahela Jayawardene stroked a brilliant 84 off 81 balls taking Sri Lanka to 253 for eight.

A 41-run last wicket partnership between Clint McKay (30) and Xavier Doherty (15) almost saw their team home but in the end Australia were bowled out for 233 in 42.3 overs.

Earlier Sri Lanka, put into bat, were straight away on the back-foot, losing Kusal Perera (4) and Kumar Sangakkara (3) with the score on 20.

Tillkaratane Dilshan (34) and Lahiru Thirimanne (57) brought the Lankans back on track with a 72-run stand for the third wicket.

It was a Jayawardene masterclass from thereon in as the diminutive right-hander stroked 11 boundaries and took his team to a fighting total.

The key, though, was the 65-run partnership that the former captain forged with Dinesh Chandimal (31).

Australia, who needed to reach the target in 29 overs for a place in the semifinal, lost the dangerous Shane Watson (5) in the second over. Phil Hughes (15) too didn't stick around for much longer as the Australians went hell for leather to achieve the target as quick as possible.

Lasith Malinga disturbed the timber, yorking Glenn Maxwell, who had struck five fours and a six in his innings of 32 off 25 balls.

The Aussies looking for the quick runs scored at a phenomenal rate but kept losing wickets in the process.

It seemed as Adam Voges (49) would take his team to victory but a rush of blood cost him his wicket.