"'Paa' will be his best performance till date but at the same time with every character Paa plays, he improves and gives his best. I would say that he always comes out with his best till date with every new role," Abhishek said in an interview.

The 34-year-old had earlier created a world record for covering the most number of cities in a promotional tour for 'Delhi 6' and now he becomes the first actor to play reel life father to his real life father, megastar Amitabh Bachchan, in their home production.

But the actor chooses not to bask in that glory and says that it will be his father's best performance till date.

In the movie, director R Balakrishnan, has presented the 67-year-old megastar as a child suffering from the rare disease of progeria, which makes him age fast.

Abhishek said that he instantly agreed when Balki narrated him the story as it was a lifetime opportunity for him.

"When Balki first told me, 'I want you to play father and son' my first reaction was 'What's new in that?', he then added 'I want you to play the father and Amitabh Bachchan the son'. This was an opportunity of a lifetime," he said.

The actor who has shared the screen with his legendary father in films like 'Bunty aur Bubli', 'Kabhi Alvida Na Kehna', 'Sarkar', said that he enjoyed the father-son bond on the sets of their latest film.

"Balki's brief to me was very simple, I had to be best friends with my father's character 'Auro' throughout the film, and since Paa and I are best of friends in real life too I really enjoyed playing Paa's Paa!" said the actor. When asked whether it was tough playing the father of his real father, Abhishek said that he enjoyed the unique experience throughly.

"Actually, it has not been tough at all. I would say it was the exact opposite, it was a lot of fun," he said.

The film has created a buzz with Big B's turn as a 11-year-old 'Auro' and Abhishek reveals that he has seen several new dimensions to his father's acting during shooting.

"I see him evolve and improve every passing day. He is reinventing himself on a daily basis. Every time he faces a camera he gives a new and fresh dimension to his performance," he said.

Abhishek who finally tasted commercial success with films like 'Dhoom', 'Guru' and 'Dostana' after a series of early flops in his career, admits that box office records do matter a lot.