Australia were 303 for three on Day One here, with Clarke, who won the toss, 125 not out. Steven Smith, who survived two unsuccessful England reviews as the hosts used up all their challenges for the innings, was 70 not out after so far helping Clarke add an unbroken 173 for the fourth wicket.
The tourists lost just one wicket in the session when opener Chris Rogers, in sight of a maiden Test hundred, was lbw to off-spinner Graeme Swann for 84.
In a match Australia, 2-0 down, had to win to regain the Ashes — a drawn series would see holders England retain the urn — Clarke opted to bat first after winning the toss despite his side being dismissed for just 128 in the first innings of their 347-run second Test defeat at Lord’s.
Although Australia had recalled David Warner, usually an opening batsman, they stuck with all-rounder Shane Watson and left-hander Rogers as their first wicket duo.
The pair responded by putting on 76 before Watson was caught at first slip by England captain Alastair Cook for 19 off first change Tim Bresnan after James Anderson, on his Lancashire home ground, and Stuart Broad had seen several good outswingers go unrewarded.
The 35-year-old Rogers scored briskly to complete a 49-ball fifty, including 10 fours, with two successive boundaries off Anderson.