Sydney, Jan 4 (IANS) Australian captain Michael Clarke notched up his 18th Test century while Ricky Ponting was stranded on 97 as the hosts reached 236 for three in the first innings, in reply to India's 191, at lunch on the second day of the second cricket Test at the Sydney Cricket Ground (SCG) here Wednesday.

Clarke was unbeaten on 103, his fourth century as a captain, and his predecessor Ponting was just three short of what could end a two-year drought since his last Test century.

Australia, resuming at overnight 116 for three, scored 120 runs in the first session and took a lead of 45 runs after the first session's play on the second day.

Clarke produced one of the best knocks of his career but that was overshadowed by Ponting's career-defining innings, which could help him retain his position in the Australian team until at least the end of the summer.

Clarke achieved the century in the last over of the morning session while Ponting have to wait before getting his much deserved century.

The duo joined forces at 37 for three during opening day's last seesion and with their 199-run unfinished stand for the fourth wicket took Australia to a position of strength to take a 2-0 lead in the four-Test series.

India failed to threaten the Australian batsmen and Clarke brought up his 50 on the first ball he faced this morning, clipping Zaheer Khan off his pads to square leg to bring up his first half century of the series.