Who plays the female lead in the 2000 film "Erin Brockovich"?

Explanation

Erin Brockovich is a 2000 biographical film directed by Steven Soderbergh. The film is a dramatization of the true story of Erin Brockovich who fought against the US West Coast energy corporation Pacific Gas and Electric Company (PG&E). One day during work she finds a suspect real estate purchase which she decides to investigate further, thus undigging a complicated case of ground water contamination. This is where the real story starts. Julia Roberts won an Oscar for her performance as Erin Brockovich.