You've got to have heart, the song says, but a good backhand doesn't hurt.

The 64 players who attempted to qualify for the ninth annual Washington Star International Tennis Championship all had heart. Many withstod two days of tough competition on 100-plus degree courts, all for a chance to compete for a few more days.

Some of them made it - Doug Crawford, Eliot Teltscher, Howard Schoenfeld, Bruce Manson, Marcelo Lalra, Ricardo Ycaza, Chris Lewis and Larry Gottfreid. Many didn't. Most were satisfied just into the qualifying round.

Dr. Ray Lake of Bethesda, a research psychiatrist, just appeared Saturday morning and accepted into the qualifying event. That's all he was looking for.

"I'm happy just to qualify." said Lake, who lost to Teltscher in the opening round. "It's a prestige thing to play in.

"It's the only tournament where things are done right. There are good linesmen, ball boys. Cokes and towels. Th courts are in good shape. These are good matches. It's a good chance to play someone not from the area."

Rodnell Collins of Marietta, Ga., has attempted to qualify in three Grand Prix tournaments this year. He hasn't made any. But he's not giving up.

"I've got a point I want to prove," he said. "I know I can do it, but sometimes my concentration is bad. I've set a time frame for myself and if I don't meet that, then I'll forget it. But not until."

John Lucas, former Maryland All-America, always has the National Basketball Association to fall back on. maybe that's why he took his 6-1, 6-1 losses to Ycaza so graciously.

"This is only the second day all summer I've played tennis," Lucas admited. "Yesterday was the first. I just ran across an excellent clay-court player. But I like tennis, I enjoy playing. It keeps me in a competitive mood." He added that he also played basketball both days.

The qualifiers who advanced to the tournament had their hands full with tennis. They represent a variety of talent and backgrounds.

Crawford, who ranked No. 42 in 1975, is recovering from a bout of tennis elbow. A Newton, Mass., native, he played college tennis with Fred McNair at North Carolina. He beat Francisco Gonzalez of Puerto Rico yesterday, 6-4, 6-2.

Teltscher, of Paolos Verdes, Calif., will enter UCLA in the fall. He advanced to the third round of Wimbledon this year and is ranked seventh among players 18 and under. Yesterday he defeated Ali Madrani of Iran, 6-4, 6-4.

Schoefeld, who outlasted Butch Seewagon of Riverdale, N.Y., 6-2, 6-7, 7-5, was the No. 1 junior in 1975. He passed up college.

Mexico's Lara, a 6-0, 6-1 winner over Terry Ryan of South Africa, is a former University of Southern California player. He has played in the Davis Cup in Mexico and has teamed with Raul Ramirez in doubles.

Ycaza, the No. 1 singles player in Ecuador, had been a surprise in the qualifying rounds. He topped Jeff Austin of Rolling Hills, Calif., 3-6, 6-1, 6-0, yesterday. Austin is the older brother of 14-year-old Tracy Austin who lost to Christ Evert in women's play at Winbledon this year.

Lewis, who beat Tony Giammabva of Houston, 1-6, 6-0, advanced to the semifinals in NCAA competition this year. A member of the Junior Davis Cup team, he plays doubles at the use with Manson.

Manson, another Junior Davis Cup player, has been an All-America at the Southern Cal. he is ranked No. 45 in men's competition, manson beat Chris Sylvan of Los Angeles, 4-6, 7-6, 7-5.

Gottfried who defeated Joagium Rasgado of Brazil, 6-4, 6-7, 6-2, is the No. 1 junior player. He is the younger brother of the tournament's No. 2 seed, Brian Gottfried.

The song says you've got to have hope too. A defeated Lake admitted, "Most players hope to win three matches and get in. I had a chance in my match. I didn't win, but I didn't get demolished." Which is all that most of these players, hope for.