In her tribute published in HT, Tagore said: "After Shammi Kapoor and Dharmendra, my most successful and popular co-star was Rajesh Khanna. My career's biggest hit, Aradhana, was with him in 1969."
"He did not have the regal looks of Dev Anand or the height and blue eyes of Shammi Kapoor, but had the charm of the boy next door with an endearing smile."
Tagore said Khanna was the master of emotions.
"Rajesh Khanna expressed emotions straight from his heart. He also lip-synced very well. When he lip-synced Kishore Kumar's songs, it appeared that he was singing them, she said.
Remembering his expertise at emoting, Tagore said: "We were cast together again by director Shakti Samanta in 1971 in Amar Prem - a remake of the Bengali film Nishipadma. In the film, Rajesh Khanna had an emotional dialogue which he delivered to me after I completed the song Raina Beeti Jaye: 'Aap ruk kyun gaye, gaaiyye na (Why did you stop? Please sing on)'. He delivered the dialogue with so much emotion and sensitivity that it left me spellbound."
"In the last scene when he bids goodbye to me and Vinod Mehra, saying, 'Pushpa', he mingled smile and tears like no other actor of that period could," Tagore said in her tribute in HT.
Tagore said Khanna had crazy female fan following that no actors had at that time.
"I have very fond memories of him. One of them is the premiere of Aradhana. There used to be no film promotions at that time but we used to have gala premieres. I was completely overwhelmed to see the crazy female following he had. Girls had lined up the streets and were screaming his name," she said.
Tagore said Khanna should not has resigned as an actor so soon.
"I have a big regret and grudge -- the only one I had against him. He should have acted more and not joined politics. He was my age and had a long career ahead of him. He could have gone on to act like Amitabh Bachchan has. Anyway, it was his personal decision," she said.
"After he got into politics, there were fewer interactions. We would just bump into each other at events. I attended his younger daughter's wedding as I was invited by the groom's side (the Thapars) as a family friend. I last met him at a function in Kolkata but could barely recognise him - he had lost so much weight," Tagore said.
"There were also discussions about us working in a film together but it didn't work out because the offer wasn't that good," she said.
"No other actor rose to such heights of fame within a span of a few years as Rajesh Khanna did. He indeed was the original superstar," Tagore said in her tribute in HT.
Khanna and Tagore together gave numerous superhits like Daag, Chhoti Bahu, Raja-Rani, Maalik, Amar Prem, Aradhana, Safar and Avishkaar.
Khanna breathed his last at his Mumbai residence on Wednesday after prolonged illness. Reports said he was battling cancer. He was 69.
His last rites were performed on Thursday.