Peter Siddle grabbed five wickets to help Australia to a 141-run lead at the end of the third day of the first Test but only after a brilliant 147 from Sri Lanka’s Tillakaratne Dilshan had stalled the hosts for much of the day.Openers Ed Cowan (16) and David Warner (eight) added 27 without loss to Australia’s first innings tally of 450 for five declared before the close of play, despite a rain disruption and some tight bowling from the Sri Lankans.Dilshan earlier put on 161 in a record partnership with all rounder Angelo Mathews (75) to drive the tourists to 336 all out after they had resumed in a big hole at 87-4 in the morning.Siddle finally separated them when he trapped Mathews lbw before tea after two sessions of frustration for Australia, which were compounded by an injury to seamer Ben Hilfenhaus.Opener Dilshan followed soon afterwards - the victim of a superb yorker from left-armer Mitchell Starc - and Siddle then skittled the tail to finish with figures of 5-54.Barring a couple of run-out chances and a few loose shots, the remaining Australian bowlers failed to create many opportunities before lunch on a good Hobart track.Dilshan, resuming on 50, had to temper his aggressive instincts but moved steadily towards his 15th Test century, spending a nervous half an hour in the nineties before finally reaching the hundred with his 16th four.The 36-year-old’s delight at completing his first century in Australia was made clear to everyone in the ground by the huge yelp he emitted as he skipped down the wicket in celebration.His hundred came off 148 balls and the scoring rate slowed even further after lunch as Australia’s bowlers took the new ball and made the batsmen work for every run.Siddle finally made the breakthrough when he sent down a delivery that caught Mathews on the back leg with the TV umpire confirming upon appeal that the ball would have clipped the top of the middle stump.