COLOMBO : Australian captain Michael Clarke burst into form with a brilliant century as the third and final cricket Test against Sri Lanka headed for a draw in Colombo on Tuesday.Clarke made 112 as the tourists, trailing by 157 runs after the first innings, piled up 429-5 in their second knock by tea on the fifth day, a lead of 272 runs with five wickets in hand.Michael Hussey followed two successive hundreds in the series with 80 not out after helping Clarke add 176 runs for the fifth wicket to frustrate Sri Lanka's bid for a series-levelling win.Australia need to play out the last session to clinch a 1-0 series win after the 125-run victory in the first Test in Galle.The second Test in Pallekele ended in a rain-affected draw.Clarke, who went 23 innings without a Test century since making 168 against New Zealand in March last year, hammered 14 boundaries and three sixes to end his drought.The hundred left him on the doorstep of a series win in his first Test tour as captain after replacing Ricky Ponting at the end of the World Cup in April.Clarke eventually lost concentration following a brief verbal skirmish with Sri Lanka's Kumar Sangakkara and holed out in the deep to give left-arm spinner Rangana Herath his fifth wicket of the innings.Left-hander Hussey continued his remarkable form, taking his run aggregate to 450 runs in five innings with two centuries.Clarke and Hussey came together after Sri Lanka had struck an important blow in the sixth over of the day, dismissing century-maker Phil Hughes.Australia had added just 11 runs to their overnight score of 209-3 when Hughes top-edged a sweep off Herath to Lahiru Thirimanne at square-leg.The left-hander made 126, his third Test century.Herath, the lone wicket-taker in the innings, shared the second new ball which was taken in the 87th over with the total 268-4.Clarke responded to the gamble by driving the spinner through the covers and lofting the next ball for six to bring up his half-century.The Australian captain failed to add to his lunch score of 71 when wicket-keeper Prasanna Jayawardene missed a difficult stumping chance off Herath.Clarke reached his century by pulling the spinner to mid-on for his 14th boundary, soon after he had smashed the bowler for his third six.