Leeds led 3-1 at the interval with Jess Clarke hitting the opening goal and Amanda Barr getting two either side of Katie Anderton's reply for Rovers.
When the visitors then lost Jane Eadie with a suspected broken ankle and went a further goal behind through Sue Smith, defeat looked definite.
But after Natalie Preston had reduced the arrears, Anderton - with her 15th goal of the season - gave Blackburn some hope.
And, with four minutes left, Preston grabbed her second goal of the afternoon to claim an amazing point.