Mel Gibson's first starring role in eight years still wasn't enough to topple the mighty Avatar from the top of the American box-office charts.

Edge of Darkness, which see's Gibson's Boston detective go on a revenge tinted investigation into the brutal slaying of his daughter, opened to a strong $17.1 million. Avatar held steady with an estimated $30 million to take its total to $594 million - it has now crossed the $2 billion mark worldwide and is still pulling in crowds. Elsewhere, the Disney romantic comedy When In Rome, starring Kristen Bell, also opened solidly with $12 million.

Edge of Darkness is out now in Irish cinemas, as is Avatar - in case you live under a rock.