Roseau, Dominica: Ed Cowan and Ricky Ponting both hit half-centuries on Wednesday as Australia built a healthy lead of 310 on the third day of the third and final Test at Windsor Park. Ponting topscored with 57 while Cowan contributed 55 as Australia reached 200 for 6 in their second innings by close.The 37-year-old Ponting, in what is likely to be his last Test in the Caribbean, struck four fours off 130 balls in 3Â¼ hours. Left-hander Cowan hit five boundaries off 123 deliveries in 161 minutes.There were two wickets apiece for off-spinners Narsingh Deonarine (2 for 28) and Shane Shillingord (2 for 69) and pacer Kemar Roach (2 for 40).The visitors had earlier secured a first-innings lead of 110 after the West Indies were bowled out for 218 having resumed on 165 for 8. Shivnarine Chanderpaul topscored for the hosts with 68 while off-spinner Nathan Lyon (4 for 69) and left-arm pacer Mitchell Starc (2 for 29) led Australia's attack.Australia found it difficult to dislodge Chanderpaul and his overnight partner, Ravi Rampaul, in the morning session. Rampaul contributed 31 and his partnership with Chanderpaul grew to 66 before the visitors broke through. Rampaul, after hitting five fours in 31 off 50 deliveries, tried to launch Lyon into the leg-side stands and only skewed a catch to backward point. Chanderpaul and last man Roach further frustrated the Aussies in a stand of 32 before the second new ball ended the defiance as Chanderpaul was plumb leg before to Starc.David Warner (11) edged Roach to first slip as Australia limped to lunch at 18 for 1, and the West Indies were boosted again straight after the break when Shane Watson (5) turned a catch to backward short-leg off Shillingford to leave Australia in peril at 25 for 2. But Cowan and Ponting rode some anxious moments at the start of their innings to build a solid stand of 87 for the third wicket. The pair went to tea at 84 for 2 and gradually blossomed after the break.Cowan's fifty arrived first, off 107 deliveries, but he departed soon afterwards as Darren Sammy grasped a sharp catch at first slip off Deonarine. Ponting's half-century nearly did not materialize as the veteran almost ran himself out going for a frantic single to reach his landmark. The throw from Adrian Barath just missed with Ponting a yard short. But the former captain and Michael Clarke added a further 56 for the fourth wicket to solidify Australia's position of strength.Ponting could not press on and Roach claimed him in bizarre fashion as he tried to duck a bouncer. The ball cannoned off the back of the bat and looped to slip. Clarke followed for 25, at 171 for 5, top-edging a pull at Shillingford. Deonarine added the wicket of first-innings century-maker Matthew Wade late in the day, plumb leg before.Michael Hussey survived to the close on 17 not out, lucky to be there as an lbw decision that went in his favour looked plumb, but the West Indies had already wasted both of their reviews. Ryan Harris was unbeaten on 4 at the close.