New Delhi: Filmmaker Karan Johar, who has watched the preview show of 'The Dirty Picture', is bowled over by Vidya Balan's performance and says she has set a benchmark for the current rung of actresses.

“Her performance in 'Dirty Picture' is by far the bravest and best performance I have seen of any actor in years....she is the benchmark,” Johar posted on his Twitter page.

“Every mainstream actress needs a grand lesson from Vidya Balan on how to submit and give your head and soul to a role...she is beyond words,” he wrote.

Not just this, Johar is also impressed the way director Milan Luthria has executed the story.

'Take a bow team Balaji!!! Super film!!! Rajat's brilliant dialogue...Milan's nuanced and superb control over the plot...dirty picture rules,' he added.