SYDNEY  - Michael Clarke posted the highest score by an Australian at the Sydney Cricket Ground and Ricky Ponting struck his first Test century in two years as the hosts pounded India in the second Test Wednesday.

Captain Clarke scored an unbeaten double-century and Ponting broke through for his first hundred in 34 Test innings in dramatic style to put Australia a commanding 291 runs in front with six wickets left and three days to go.

The pair shared the biggest partnership -- 288 runs -- for any Australian wicket against India to leave the dispirited tourists with a mountain to climb to save the four-Test series after going down by 122 runs in last week's opener in Melbourne.

At the close on the second day, Australia were 482 for four with Clarke unconquered on 251 off 342 balls and Mike Hussey on 55. The pair had put on an unfinished 157 for the fifth wicket. Ponting, 37, gave the perfect riposte to those calling for his retirement with a dogged 134, while Clarke basked in the adulation of his home crowd by surpassing Doug Walters' previous highest SCG score by an Australian of 242 set in 1969.

The Australians, trailing by 75 at the start of the day, lost only one wicket in a dominant day's cricket after the helter-skelter of 13 wickets tumbling on Tuesday. "We need to bat well tomorrow morning to set up the game and then we need enough time to bowl India out," Clarke said.

"So we're a long way from being 2-0 up, a lot of hard work has to go in over the next three days, but we're in a really good position." While the first day's play was all about wickets, Wednesday's action was purely about runs as Australia set about building a massive lead to chase after a 2-0 series lead.

Clarke brought up his 18th Test century and fourth against India with a glorious cover drive off Ishant Sharma in the last over before lunch. He went on with the job of surpassing his previous Test best 168 against New Zealand in March 2010 and offered only one chance on 182, that Sharma dropped him off his own bowling.

"What makes me proud is that I batted the whole day, that's something I've always tried to do and haven't done very often, so that's very satisfying to bat out a full day," Clarke said. Ponting meanwhile scampered off for a single on 99 to mid-on and flung himself full-length to make his ground as Zaheer Khan's throw whistled past the stumps at the bowler's end 20 minutes after lunch.

The former skipper clambered off the ground, his shirt coated in dirt, smiling broadly and with his bat raised to mark his first hundred since his 209 against Pakistan in January 2010. "I know that I was probably out by two yards if the ball hit the stumps," Ponting said.

"Bit of brain fade I guess, I hit it through the gap and it just got to him quicker than I thought it would. Thankfully he missed or it would have been a pretty sad end to what could have been a good day." It was his 40th Test century and sixth at the SCG, where he is also the leading all-time Test run-getter with 1,480.

Ponting was finally out shortly before tea when he sliced to Sachin Tendulkar in the gully off Sharma. He batted for 335 minutes, faced 225 balls and hit 14 fours. Australia's run onslaught exacted full toll on India's mediocre 191 first-innings total, leaving the tourists with a massive task just to get the home side to bat a second time in the match.

"It's going to be a catch-up game from now on," Indian spinner Ravi Ashwin said. "We're going to have to try to dig deep and bat long and hard and one or two will have to stand up and really make it count." Clarke and Ponting came together late Tuesday with Australia at a shaky 37 for three and put the home team in an impregnable position to force a result.

Hussey carried on his form from his 89 in Melbourne with a flourishing half-century, with his 50 coming off 70 balls and featuring one straight-hit six off Ashwin. India have never won a Test series in Australia.