Kabir Khan's directorial "Phantom", on the post-26/11 Mumbai terror attacks, grossed Rs.8.45 crore on its opening day in the country.
The Saif Ali Khan and Katrina Kaif starrer released on Friday, a day ahead of the festival of Raksha Bandhan.
"We are overwhelmed with the response. It's an amazing beginning," producer Sajid Nadiadwala said in a statement.
The film's day one box office collection also marks as Saif Ali Khan's highest opener since 'Cocktail', a source said.
Since Raksha Bandhan is being observed on Saturday, it's expected to contribute further to the revenue growth of "Phantom", and the numbers are expected to witness growth over the weekend due to the buzz around the movie.
The action thriller, which revolves around global terrorism, is an adaptation of the novel "Mumbai Avengers". The espionage drama is based on the terrorist attacks in Mumbai which took place on November 26, 2008.