The Australian opener, let off on nought and 37, made an unbeaten 101 for his second Test hundred to help his side recover from an early blow with a 141-run stand for the second wicket with skipper Ricky Ponting (71).
Watson, who cracked a century in each innings of a practice game before the Test, completed his hundred in the final session when he turned off-spinner Harbhajan Singh to deep square-leg for two runs.
He has so far cracked eight fours in his 279-ball knock. Tim Paine was the other not-out batsman on one.
India did not allow Australia to seize the initiative despite Watson's hundred as left-arm paceman Zaheer Khan grabbed three big wickets, including two in the final session.
Australia, who scored 101 runs in the morning after electing to bat on a pitch lacking pace and bounce, could manage only 45 in the last session. Even Watson could add only 26 to his tea score of 75.
"To get a hundred is good as the conditions are different and it tested my concentration. It was all about playing the ball on its merit and try and rotate the strike," said Watson.
"Indians bowled well after Ricky's run-out, so our run-rate dropped in the session. Then the ball started to reverse-swing and Zaheer is a very good bowler, so we couldn't score much."
Left-arm spinner Pragyan Ojha kept a tidy line and length, conceding just 39 runs in 31 overs.
Australia were comfortably placed at 154-1 before slipping to 222-5, losing well-set Ponting, vice-captain Michael Clarke (14), Hussey and North.
Ponting, averaging just 20.85 in 12 Tests in India before this match, looked set to play a big knock before he was run out by Suresh Raina's direct-hit at the striker's end from mid-wicket.
Words were exchanged between Zaheer and Ponting after the Australian skipper's dismissal. Ponting hit 10 fours in his 124-ball knock.
"I think when you play a tough game and expect a tough competition, words are exchanged. You know you play hard and sometimes this happens," said Ojha.
"It was great the way we came back in the Test, getting wickets. At the end of day, we got five wickets which make the match evenly poised."
The Australian captain produced some delightful strokes during his stay at the crease, driving Ojha through the covers to reach his half-century and then square-driving and flicking Zaheer for two fours.
India were left a bowler short in the afternoon when paceman Ishant Sharma departed the field during his eighth over with a leg injury.
Zaheer, returning to the Test squad after missing the recent Test series in Sri Lanka due to injury, was unlucky not to dismiss Watson with his second delivery as Virender Sehwag dropped a catch at gully.
The fast bowler did not have to wait long for his first success, trapping Simon Katich (six) leg-before in his third over.
India introduced spin after 10 overs on a slow track, but Ojha and Harbhajan could not break the Ponting-Watson stand in the morning.
Watson was lucky to survive on 37 when wicket-keeper Mahendra Singh Dhoni failed to hold on to an edge off Ojha.
He played some handsome shots, straight-driving Sharma and then pulling Zaheer for two fours. He then struck two successive fours off Sharma before the paceman left the field.
Harbhajan, a doubtful starter on Thursday due to a leg injury, was declared fit in the morning.
Source: AFP South Asian Edition