"I have accepted that Rohit Shekhar is my son. The DNA test also proved he is my biological son," Mr Tiwari told NDTV, his first ever public acknowledgement of the 34-year-old and his mother Ujjwala Sharma.
On Sunday night, Mr Tiwari invited Rohit to his guest house in Delhi and spoke to him for the first time in years, reportedly telling him that he was tired of fighting.
"I am proud of my association with this great family," said the 89-year-old.
Mr Tiwari, who has been the governor of Andhra Pradesh and Chief Minister of Uttar Pradesh and Uttarakhand, fought his son all the way to the Supreme Court before arriving at this point where they all could sit together as a family.
Rohit Shekhar went to court against Mr Tiwari in 2008, claiming he was born out of an affair between the Congress leader and his mother. He said he only wanted to be acknowledged by the man who attended his birthday parties and played with him when he was a child.
In 2012, Mr Tiwari was forced to give samples of his DNA for a paternity test after warnings by the Delhi High Court, which even authorized the police to enforce its order, if needed. He even moved Supreme Court against the test but failed to stop it.
"What my mother and I went through...the scars, the pain, I don't want anyone else to go through. I hope we can heal the wounds," said Rohit, 34. He says in course of his battle, he suffered a heart attack and developed chronic insomnia.
He admitted that being accepted was just the first step in putting the bitterness behind. "The wounds will not go away even if I pretend. But all I want now is to spend some time with him. Our case has set a precedent and, hopefully, will help others who have gone through this," he said.
Asked whether he would like to spend more time with his new son, Mr Tiwari replied, "Why not?" Rohit says he would like to get to know his father and be with him, even if it involves helping him campaign for the Lok Sabha polls in three months.
Get the latest election news, live updates and election schedule for Lok Sabha Elections 2019 on ndtv.com/elections. Like us on Facebook or follow us on Twitter and Instagram for updates from each of the 543 parliamentary seats for the 2019 Indian general elections. Election results will be out on May 23.