Rising all-rounder Reddy was applauded off the Melbourne Cricket Ground on 105 not out after rain ended play for the day midway through the final session.
Having provided much-needed stability to another shaky Indian batting effort, the 21-year-old will resume on Sunday alongside Mohammed Siraj, on two, with the first-innings deficit reduced to 116 runs.
Australia’s push for a much bigger advantage after scoring 474 was stymied by Reddy and spin-bowling all-rounder Washington Sundar, who scored 50 as the pair put on 127 for the eighth wicket.
To the roar of a large contingent of Indian supporters among a record 83,073 third-day crowd at the MCG, Reddy lofted Scott Boland over mid-on to reach three figures just before play was halted.
It was an innings memorable for resolute defence, mixed with classical strokeplay.
Reddy faced 176 balls, hitting 10 fours and one six, continuing the fine batting form that has marked his debut series.
In his first six Test innings, he has scored 284 runs at an average of 71.
Seamers Boland, who took 3-57, and Pat Cummins with 3-86 were the most productive Australian bowlers in conditions that offered little assistance despite overcast skies.
The recalled Sundar’s dogged knock off 162 balls ended when he was caught at first slip by Steve Smith from off-spinner Nathan Lyon.
It ended a partnership that traversed the entire second session after India had advanced from 164-5 overnight to 244-7 at lunch.
Sundar survived the most freakish moment of the day when on 18.
Attempting to flick a leg-sided delivery from Mitchell Starc, the ball flew from the back of the bat into the slip cordon where a diving Smith spilled a one-handed opportunity.
India lost Rishabh Pant and Ravindra Jadeja in the opening session.
Pant’s innings of 28 ended when he over-balanced while attempting a ramp shot for six off Boland, top-edging the ball to third man where Lyon held the catch.
Jadeja was trapped lbw when on 17, playing back to a Lyon delivery that skidded on.
The crowd of 83,073 was a record for the third day of a Boxing Day Test, according to Cricket Australia, and the largest day three crowd at the Melbourne Cricket Ground since 1937.
The record total attendance for a Boxing Day Test is 271,865, which looks certain to be smashed on Sunday after 255,462 spectators came through the gates on the first three days.
Rain threatened throughout the day and about 40 minutes of play was lost in a period either side of tea.
The series is locked at 1-1 with the fifth and final Test to be played in Sydney next week.
AFP
