Mitchell Starc (3) has cleaned up by Ravindra Jadeja in the next over. Peter Siddle has come out to join his captain.
A boundary off Jadeja, his 11th, helps Clarke reach a deserved hundred in the day's final over.
It is his 23rd Test ton, his sixth against India.
Australia end the day at 316 for seven (after 95 overs).
Clarke remains unbeaten on 100 and Siddle on one.
The visitors reached the 300-run mark in the 88th over, courtesy a Henriques' boundary off Kumar.
However, two overs later, Ashwin yet again gave India a vital breakthrough by trapping Henriques (68) plumb in front.
The debutant's 132-ball knock included just five boundaries but he helped his captain add 151 runs for the sixth wicket.
Australia 307 for six after 90 overs.
Clarke and Henriques have combined superbly here in Chennai. It is exactly what the Australian think tank would have wanted, a stable partnership.
The sixth wicket stand has yielded the team more than hundred runs.
A single off Ishant helps Henriques complete his half century on debut.
Australia 262 for five after 78 overs.
Ishant Sharma replaces Jadeja (third spell, 8-0-24-0) in the attack in the 60th over. He gives away two runs.
A single by Henriques off Harbhajan helps the visitors reach the 200-run mark, in what is the 61st over.
Another single by him in Ishant's next over helps raise the 50-run partnership for the sixth wicket.
Australia reach 215 for five at tea (66 overs).
Clarke is unbeaten on 45 and giving him company is Henriques (on 29), the two having put on 62 runs for the sixth wicket thus far.
Having suffered three reverses at the start of the second session, the visitors have recovered to an extent.
And leading the recovery is their captain. Clarke, with debutant Moises Henriques for company, has so far added 42 runs for the sixth wicket.
Australia 195 for five after 59 overs.
The loss of the two set batsmen soon after resumption has put the visitors on the back foot.
The onus is now on their captain to wriggle them out of the tough situation and wrest back the initiative.
It will be a difficult ask though with the wicket turning a lot and the home team using only its spinning options.
A boundary by Matthew Wade off Ashwin helps the visitors reach the 150-run mark, in the 45th over.
Australia 152 for four after 45 overs.
Ashwin strikes twice after lunch to dismiss both Watson (28) and Warner 59.
Michael Clarke has also completed 7,000 Test runs, and in the process gone past Sir Don Bradman.
Australia 145 for four after 42 overs.
Jadeja replaced Ashwin (11-2-30-2) at the other end.
Australia head into lunch comfortably placed at 126 for two (34 overs).
David Warner is batting on a well-made 58 and giving him company is Shane Watson on 28, the two having put on 54 for the third wicket thus far.
Ashwin has picked up both the Australian wickets to fall in the opening session.
Ishant is back into the attack in the 20th over, replacing Harbhajan (7-1-29-0). He gives away five runs, including a boundary to Watson.
Ishant has looked off-colour today and is soon replaced by Ravindra Jadeja, in the 22nd over. He gives away four runs first up.
The visitors reach the 100-run mark in the 28th over, courtesy a single by Warner off Jadeja.
Harbhajan replaces Jadeja (4-2-11-0) in the attack in the 30th over. A couple off his second ball helps Warner reach his sixth Test fifty.
Australia 112 for two after 30 overs.
Phil Hughes (6) doesn't survive for long either, Ashwin making him play on to his wickets. Two wickets in quick time here.
Australia 72 for two after 19 overs.
Shane Watson comes out to bat.
By the way, the second Test stays in Hyderabad, and not moving to Bangalore as reported.
India finally get the much-needed breakthrough, Ashwin having Cowan (29) stumped.
Australia lose their first wicket at 64.
Phil Hughes comes out to join Warner.
Spin is introduced in the attack as early as the sixth over, Harbhajan Singh replacing an expensive Ishant (2-1-12-0).
The offie, playing in his 100th Test match, gives away five runs first up.
Ashwin replaces Kumar (4-1-15-0) in the attack in the ninth over and is unlucky not to get a wicket in his third ball as Sehwag puts down Warner (on 18) in the first slip.
This, by the way, is Ashwin's first Test at Chepauk.
Australia 50 without loss after 10 overs.
The first boundary of the Australian innings comes in the third over, courtesy a pull by Cowan.
The fourth over by Ishant witnesses the bowler conceding three boundaries, Warner hitting one over the square leg first before Cowan despatches the final two deliveries.
Warner helps himself to successive boundaries in Kumar's third over.
Australia 29 without loss.
India have made the shocking decision of dropping Pragyan Ojha, their best bowler against England, and hand a Test debut to Bhuvneshwar Kumar.
The latter opens the bowling. David Warner and Ed Cowan to start the batting for Australia. Two runs off the first over.
Ishant Sharma to bowl with the second new ball. He concedes a single.
Australia three without loss.
MS Dhoni (captain), Virender Sehwag, Murali Vijay, Cheteshwar Pujara, Sachin Tendulkar, Virat Kohli, Ravindra Jadeja, R Ashwin, Harbhajan Singh, Bhuvneshwar Kumar, Ishant Sharma
Michael Clarke (captain), David Warner, Ed Cowan, Phillip Hughes, Shane Watson, Matthew Wade, Moises Henriques, Peter Siddle, Mitchell Starc, James Pattinson, Nathan Lyon
Australia won the toss and Michael Clarke had no hesitation in opting to bat first in the opening Test against India at the MA Chidambaram stadium on Friday.
"We were definitely going to bat first," he admits.