At last night's opening of the South African drama, " 'Master Harold' . . . and the boys," the theatrical powers on stage and the Washington powers in the Warner Theater were wrestling with similar issues of race relations and education.

In the play, the white teen-ager boasts that Churchill and Tolstoy were lackadasical about their school work. He and his families' two black workers exchange their spontaneous laughter for bitter words about the legal and emotional separation of their lives in South Africa. Last night's audience had packed the theater in support of the Black Student Fund, a local organization that for 19 years has worked at breaking the pattern of segregation in private schools.

"We are interested in the whole question of people getting ahead. In South Africa there is no opportunity and here we provide an opportunity," said Nancy (Bitsy) Folger, the fund's chairman, as she greeted the play's stars and patrons at a lively after-theater party.

"It is about learning," said James Earl Jones, the leading actor in the Athol Fugard drama. "The crucial part of Hally's education continues after the play. It does for us all."

As soon as Jones, and his costars, Delroy Lindo and Charles Michael Wright, arrived at the offices of attorney Stuart Bloch in an art-crammed 16th Street mansion, they were drawn into conversations about the play's lessons, as well as the current state of the arts.

"The play is about equal opportunity," said Wright. "In order to live in harmony everyone has to have the same opportunity." Rep. Bob Carr (D-Mich.) buttonholed Jones for a lunch next week with the Congressional Arts Caucus. "He's invited, along with 'Show Boat' star Donald O'Connor. We want to get performing professionals involved with our legislative support of the arts."

Adding their own congratulations for the performers were two students who were part of the fund's network. "He reminds me of my father," said Tiffany White, a senior at National Cathedral School for Girls, commenting on Jones' dimples and full face.

The message of the play hadn't settled on White yet. But she was disturbed by a remark she had heard at school yesterday. "Today a black student told me a white teacher said the white students were smarter," said White. "I don't recognize racism, I don't pay it attention, so I was stunned."

Franklin Davis, a senior at Georgetown Day School, told Jones he hadn't made up his mind about a career yet but "I'm definitely going to college in the fall. I am still waiting for some acceptance letters."

White and Davis are just two students the fund has matched with private schools, given financial help and then furnished with counseling. Originally the fund paid full tuition, but now, said Executive Director Barbara Patterson, the program has worked so well that the fund is paying only $640 a year per student, with the schools paying the balance.

"The fund has helped me learn, under certain circumstances I wouldn't have had, the multi-racial atmosphere at my school is wonderful," Davis said. "I have learned to appreciate the differences in others."