Smith's knock came off 305 balls with 15 boundaries and two sixes.Harris scored his third test half century in style with eight fours and a six before he was trapped lbw while attempting a big sweep off Ravichandran Ashwin (3-134).Nathan Lyon added 11 and was bowled by Shami.
Smith and Haddin turned an evenly poised match in Australia's favor with an aggressive start to the morning, sharing a 110-run, sixth-wicket partnership until Haddin (55) offered a bottom edge to India wicketkeeper M.S. Dhoni off Mohammed Shami (4-138).
Smith added another 50 runs with Mitchell Johnson, who scored 28 before being stumped off Ravichandran Ashwin (3-134) shortly before lunch.After resuming the day on 72 with Australia at 259-5, Smith brought up his century with a four down the leg side off Shami, raising his bat and helmet in celebration before an appreciative Melbourne Cricket Ground crowd.
The Australia captain's 100 came off 191 balls with nine boundaries and a six.Haddin proved an able partner at the other end, seeing off a barrage of short balls from the Indian pacemen to reach his half century off 75 balls with seven boundaries a and a six.
Smith's previous highest first-class score was 177 scored for New South Wales against Tasmania.
He has now scored 1,132 test runs this year, eclipsing Warner's 1,096.Australia can clinch the four-test series and reclaim the Border-Gavaskar trophy with a win or draw in Melbourne after a 48-run win in the first test and a four-wicket victory last week in the second test at Brisbane.
-AP