 In 1997 , her portrayal of Isha Diwan , a psychopath serial killer and obsessive lover , in Gupt : The Hidden Truth , was lauded by critics and proved to be a major turning point in her career . She explained that playing Diwan was the " toughest role " of her career as it was " difficult to play a mean character " . In an interview with The Hindu , director Rajiv Rai quoted , " [ I ] tapped the versatile artistry in Kajol in Gupt ! [ She ] had a complex role and she certainly brought a rare finesse to her etching of that character in the film " . The suspense thriller , which co @-@ starred Bobby Deol and Manisha Koirala , also emerged as a major commercial success . Kajol eventually became the first actress to be nominated in and win the Filmfare Award for Best Performance in a Negative Role . 
