After several attempts to put a hard serve past Ken Rosewall in the third set, frustrated Roy Emerson decided the only thing left was to tap in a serve.

Rosewall returned it into the net.

It was one of the few mistakes Rosewall made in the final two sets, as he improved his serve and ran Emerson along the base line in winning his E.F. Hutton Champions semifinal match, 2-6, 6-1, 6-1, last night at George Washington University's Smith Center.

Rosewall, 52, a main attraction on the Grand Masters tennis circuit, will play the winner of today's Rod Laver-Fred Stolle match in Monday's final.

In other matches, Stolle beat Neale Fraser, 4-6, 6-4, 7-5, in the men's quarterfinals and Kerry Melville-Reid won a women's semifinal over Valerie Ziegenfuss, 7-5, 4-6, 6-4. In the women's doubles final, Virginia Wade and Melville-Reid defeated Laura DuPont and Ziegenfuss, 4-6, 6-1, 6-4. Stolle-Emerson beat Fraser-Ramanathan Krishnan, 6-2, 6-2, in a men's doubles semifinal. Emerson-Wade beat Fraser-DuPont, 6-1, 6-3, in a mixed doubles semifinal.

Melville-Reid plays Wade in the women's final, at 1 p.m. today. Then Emerson-Wade meet Rosewall-Melville-Reid for the mixed doubles title.

Rosewall appeared frustrated in the first set, and at one point intentionally hit a playable ball long. "To be honest," said Rosewall. "I'd been serving so poorly, the way I hit it, I thought I had double faulted."

In the final game of the set, Emerson won every point when Rosewall couldn't return his serve, and he took the set, 6-2. "I was just getting myself upset because I wasn't getting the serve in," said Rosewall.

Emerson, 48, who had finished a doubles match an hour before he played Rosewall, couldn't get his powerful serve going in the final two sets. He also seemed tired at times on base-line shots, hitting many long.

"He just played too good," said Emerson. "He was missing a few and gave me a few shots in the first set. He didn't give me any in the second and third."

Rosewall broke serve for a 2-0 lead in the second set and put away an overhead at 40-0 to lead, 4-1. He broke Emerson's serve in the next game and won the set when he got a forehand volley winner at deuce and Emerson hit a backhand long.

Before Emerson knew it, he was down, 5-0, in the third set. Rosewall then returned two of his hard serves for winners to take a 30-0 lead. Frustrated, Emerson tapped the next serve, which Rosewall netted, then smiled.

"The harder I got a serve in, the harder he returned it," said Emerson. "So I decided to pippy the thing."

Emerson took Rosewall to deuce in the sixth game but hit two shots out and Rosewall had the match.

"After the first set, I knew I would have to concentrate," said Rosewall. "I did everything better. I returned Roy's serve better and I didn't make any mistakes."

"He put a lot of pressure on me the last two sets," said Emerson. "I couldn't make a good shot at the right time."

After Stolle, 47, won the second set of his match, Fraser broke serve at 1-1 and took a 3-1 lead with a game-winning ace. Stolle then won three straight games and broke serve to win the match. "Two hours of covering the court by yourself . . . " Fraser, 52, sighed. "The longer the match went, [the more] he was lobbing here, dropping there."