"That was right out of the top drawer. I'd probably rate that as No. 1 to be totally honest," said Pietersen, who hit a belligerent 134 that put England in a match-winning situation.
"The conditions last night and this morning were as testing as I've had them in international cricket, or county cricket for that matter."
Pietersen had been under fire for his comments a few days back that he was "mentally fatigued" by the international scheduling. Obviously his joy knew no bounds and he did an exaggerated celebration after reaching the triple-figure mark.
The South Africa-born England player said his innings was a fitting reply to his critics while reaffirming his commitment to his adopted country.
"I simply answered a simple question that I was asked last week on my time off, and it got blown up," he said.
"But I'm as committed to everything. I've never ever shied away from anything, I've always turned up for England.
"I've never ever asked for a day off, ever. As long as I'm asked to play for England, I'll play for England."
Pietersen, who hit his first century against India and the ninth overall with the help of 14 fours and one six, said it was his best performance so far.
"You could see by my celebrations (after reaching hundred) how happy I was, because that really, really was a difficult day for batting," he said.
"I do like to have fun, but this was one of those innings where I definitely played to enjoy myself. I play to express myself. But the most important thing is setting myself and the team up to win the Test match.
"That's why I gave my wicket away trying to get a few more runs. If I was playing for myself, I could have quite easily still been batting now.
"We were looking to get a 400 lead, so I was pretty cross to get out at 380, but that's the way I play, I'll do anything.
"What you guys should know is that every single time I turn up for a training session, every single time I turn up for an international, I'll never ever shy away from anything," he said.
"My celebrations were because of everything that went into this Test match as well. Everyone's entitled to their own opinion."
Pietersen also had a word of praise for Monty Panesar who struck a big blow in dismissing Sachin Tendulkar and celebrated as wildly as he could.
"Sachin's his big man, the man he's looked up to and really, really admired since he was a little boy," said Pietersen.
"So for him to get out the bloke he admires most in this world is fantastic for Monty. But it was good bowling leading up to that wicket. Full due to him, he looks like he can get a wicket every ball."