Lara hit an undefeated 178, boosted at the end of the day by blasting a Test-record 28 in one over from left-arm spinner Robin Peterson.
The West Indies captain told reporters he had been up early watching television where India were batting against Australia on the third day of the second Test in Adelaide.
India reached the close on 477 for seven in reply to Australia's first innings of 556 with Rahul Dravid on 199 not out after VVS Laxman scored 148.
"India are taking on Australia, the best team in the world, and we're taking on the second best team in the world," Lara said.
"I watched Dravid and Laxman and I used some of their strength out there today. We are the underdogs in this series and we need to fight."
Lara said of his record 28 in an over. "I had no intention of going for it. I just wanted to get as many runs as possible."
The genial Peterson, 24, said: "Hopefully I'll learn from it and be a better bowler as a result."
Peterson told Reuters: "When he hit the first ball for four me and (captain) Graeme (Smith) both thought, 'he won't try it again'.
"After the second ball we looked at each other and thought, 'he won't try it again'.
"After the third ball we thought, 'he definitely won't try it again now'. Unfortunately we thought that all through the over."
South African coach Eric Simons said: "It's part of the learning process for Robin and I don't think he will let it get him down for too long."
Lara hit Peterson for a four followed by two sixes and then three more fours.
The West Indies resume on Monday on 363 for six, still 198 behind the South Africans.
