Shah, under whose tenure the party's old guard has been eased out of the key decision-making bodies, said the generational change in the party began after the Maharashtra leader took over as its chief in 2010.
"The generational change first began under Gadkari ji's tenure... It is due to this that a new generation of leaders after earning trust (from others) are working ably in the country as well as the party," he said at the launch of the Hindi translation of a book, 'Bhawishya ka Bharat (India of future) authored by Gadkari.
He praised Gadkari for his patience and generously spending time with party workers as party chief as Shah recalled his days in Delhi where he would spend most of his time after a judicial order had barred him from going to his home state Gujarat as he was then probed in a criminal case.
Shah later got a clean chit in the case.
Speaking on the occasion, Singh, now Home Minister, said Gadkari was the brain behind the then Prime Minister Atal Bihari Vajpayee's ambitious 'Pradhan Mantri Gram Sadak Yojna' and added that his alternative economic model could be of help in making India a developed country.
Describing Gadkari as a person with big heart, he said this was the reason behind his happiness in most adverse conditions and added that those with small hearts can never be happy.
In his address, Gadkari said merely change of government cannot bring about social changes and nation-building and work at the grassroots level involving the poor and deprived could do that.
He said Prime Minister Narendra Modi has given a new direction to the country and said it was the government's responsibility to use power it has to change the people's conditions.
he dedicated his book to a teacher working in an organisation run by him whose limbs were cut off by naxals but he kept working.