Kusal Mendis' maiden Test hundred pulled Sri Lanka out of trouble as it reached 282 for six when bad light brought an early close to the third day of the first Test against Australia. Mendis was 169 not out at the close off 243 deliveries. He batted for five hours and hit 20 boundaries and a six against off spinner Nathan Lyon to bring up his century. Batting at No. 4, he shared 117 runs for the fifth wicket with Dinesh Chandimal (42) after Sri Lanka had slumped to 86 for four. Sri Lanka has a 196-run run lead with four wickets in hand with the possibility of setting Australia a challenging winning target. The second session was a productive one for the host team with 137 runs coming for just one wicket. Chandimal faced 100 balls and hit four boundaries before being trapped lbw by seam bowler Mitchell Marsh. Dhananjaya de Silva (36) and Mendis added 71 runs for the sixth wicket. De Silva was caught by Usman Khawaja to become Lyon's 200th test wicket in his 55th test. Starc had best bowling figures of two for 44 while Lyon returned two for 98. Sri Lanka resumed Thursday at 6-1 and paceman Mitchell Starc and spinners Steve O'Keefe and Lyon picked up a wicket each to contain the hosts in the morning session. Having trapped opener Kusal Perera lbw the previous evening, Starc dismissed Dimuth Karunaratne (0) lbw with the third delivery on Thursday and with Sri Lanka still on its overnight score. The batsman's review of the decision was unsuccessful. Mendis withstood the opening spell and dominated two promising partnerships, 39 runs for the third wicket with Kaushal Silva (7) and 45 runs for the fourth wicket with captain Angelo Mathews on his way to become the youngest Sri Lankan to score a test century against Australia. Silva was trapped lbw, again after an unsuccessful review, by O'Keefe. And Mathews' unconvincing innings ended when he was caught bat-pad by Joe Burns off Lyon for nine. Sri Lanka scored 117 in its first innings and Australia made 203.