Skipper Michael Clarke scored a century and Ricky Ponting was on the verge of his first Test hundred in two years as Australia tightened the screws in the second Test against India on Wednesday. The two experienced Australian batsmen batted throughout the morning session on the second day to put the home team 45 runs in front of India's modest first innings 191 with an unbroken 199-run stand. At lunch on a steamy day at the Sydney Cricket Ground, Australia were 236 for three with Clarke on 103 and former captain Ponting on 97. Ponting last scored a Test century with his 209 against Pakistan in Hobart in January 2010. The former skipper is the leading scorer in the series after hitting 62 and 60 in Melbourne last week. Clarke's 18th Test century and fourth against India came off a glorious cover drive off Ishant Sharma in the last over before lunch. It was Clarke's second Test century of the Australian summer season after scoring 139 against New Zealand in Brisbane last month. The pair were untroubled throughout the morning session against an unthreatening Indian bowling attack following the tourists' poor first innings total on a flattening SCG batting track. Clarke and Ponting came together with Australia at a shaky 37 for three and over 200 minutes' batting time later have put the home team in a strong position to force a result. India have never won a Test series in Australia and trail the home side in the four-Test series after a comprehensive 122-run defeat in last week's opening Melbourne Test.