Emma Stone had a disastrous tennis match against Billie Jean King as she prepared to play the sports star in an upcoming comedy.

The Easy A actress portrays the former world number one in the 2017 sports comedy Battle of the Sexes, opposite Steve Carell, and when Billie Jean heard the movie star needed a few lessons she invited her for a game.

Emma admits she "kept hitting clunkers" but Billie encouraged her to forget about those bad hits and stay positive for the next ball - a lesson Emma has remembered ever since.

"Let me be clear about something, I was a complete novice," she said at the annual Trailblazer Honors awards. "At that point I'd had three lessons, and she, on the other hand, is one of the greatest players of all time. So, a fair match it was not.

"What I lacked in tennis skills, I hope I made up for in my ability to connect with her essence and understand the greater lesson of what she was saying... 'Let go of the negative, stay open and positive - the next ball might just be a good one'. I feel like that's something Billie has lived by her entire life."

The 27-year-old actress appeared at the New York ceremony, an annual show dedicated to the lesbian, gay, bisexual and transgender (LGBT) community, to honor Billie, who went public as a lesbian in the 1980s.

Before handing Billie, 72, the Trailblazer Award, Emma also said, "Even in the darkest times, (Billie) was always looking forward, visualising a bigger, brighter, more inclusive future... And not just for women, not just for the LGBT community, but for anyone who ever felt marginalised."