Melbourne, Dec 27 : Starved off a century for nearly three years, underfire Australian opener David Warner respond with a brilliant double century in his milestone 100th Test, becoming only the second batsman after England's Joe Root to do so, on the second day of the second Test against South Africa at the Melbourne Cricket Ground here on Tuesday. Warner joined a special club in the afternoon session, becoming the 10th batsman to score a century in his 100th Test in the Boxing Day Test, becoming the second Aussie batter in this elite list. He went on to set an even better record, racing to his double century as Australia took the driver's seat in the second test, scoring 386/3 off 91 overs in the second Test against South Africa. Having shot out South Africa for 189 in their first innings, Australia now lead the visitors by 197 runs with seven wickets in their kitty and three days to go in the match. The credit for putting Australia in this situation goes to Warner, who scored 200 off 254 deliveries, hitting 16 boundaries and two sixes before retiring hurt, exhausted by the sweltering conditions at the MCG. Warner resurrected the Australian innings from 75/2 as he raised a double-century partnership with Steve Smith, who scored a fine 85 off 161 deliveries, hitting nine fours and one six. At stumps on the second day, Travis Head was batting on even-ball 48 with Alex Carey keeping him company with nine runs. The sweltering conditions were very tough for the hosts as Cameron Green too retired hurt when he was batting on six off 20 deliveries. The South African bowlers toiled hard throughout the day with limited success. The day belonged to Warner as he helped build Australia's response to South Africa's first innings score as the hosts, who had won the first Test at Brisbane within two days, seek to seal the three-match series by winning the second Test. Warner brought up the three figures in just 144 balls, pulling a Kagiso Rabada delivery down to fine leg for a boundary. Fighting cramps in the searing heat as he continued, Warner went on to bring up a double century with a boundary down to the third man. He was forced to retire hurt after succumbing to the conditions, though not before a standing ovation from teammates, fans and family on hand. The seasoned opener passed the 8000 Test-run mark early on day two, doing so at an average of over 46, passing Mark Waugh as Australia's 7th-most prolific run-scorer in the format. Just seven batters boast more than the 25 Test centuries for Australia than the 36-year-old left-hander, who joins Pakistan great Inzamam-ul-Haq on the mark. Beginning the day on 32, Warner looked in good touch in the early moments against the acclaimed Proteas attack, accelerating with multiple boundaries. A mix-up cost Marnus Labuschagne his wicket at the other end, though Warner continued alongside Steve Smith in Australia's assault on either side of lunch, as the hosts moved into a strong position. A partnership of 239 with Steve Smith ended when the right-hander miscued a glide behind point straight into the hands of Marco Jansen, and Warner, suffering from fatigue and injury in the heat, opted to take an aggressive approach. Warner fell to the ground upon reaching the double hundred, and his body put through a test of both mental and physical demands, broke down on him. He was helped off the field by a number of Australia support staff after retiring hurt, with Cameron Green striding out to replace him, according to a report on the ICC's official website. Building on a strong first day with the ball, Australia now enjoy a strong first-innings lead in the second Test match of the series, and look on the way to taking both the dozen World Test Championship points and an unassailable 2-0 lead. Brief scores: South Africa 189 trail Australia 386/3 in 92 overs (David Warner 200 rt hurt, Steve Smith 85, Travis Head 48 not out; Anrich Nortje 1-50) by 197 runs. /IANS