When rain forced the final of the women's Mid-Atlantic Tennis Association outdoor championship inside yesterday at Aspen Hill Racquet Club, Charlotte Haberstroh of Salisbury, Md., found the faster new surface more suited to her game, and she defeated top-seeded Laurie Macgill of Baltimore, 6-3, 6-3.

In the first set, Haberstroh, 20, who plays for the University of Richmond, used a strong serve and powerful ground strokes to hold serve throughout and eventually break Macgill in the seventh and ninth games.

Haberstroh won the set when, after a long rally in which Haberstroh hit mostly top-spin backhands and Macgill returned mostly backhand slices, Haberstroh changed the pace by hitting a drop shot that Macgill could not reach.

Haberstroh continued to use strong ground strokes to her advantage in the second set. "I thought I moved the ball well and I played to her backhand," said Haberstroh, who was seeded fourth in the 40-player draw. "Her forehand just kept driving me off the court, so I kept hitting to her backhand."

In the second set, the players exchanged breaks and each held serve twice. In the sixth game, Macgill began to use the synthetic indoor surface to her advantage.

She served and volleyed to win the first two points. Haberstroh netted a forehand, then hit a forehand long, leaving the score at three games apiece.

"At that point, I wanted to keep coming to the net," said Macgill, 21, who recently turned professional after finishing at South Florida. "But Charlotte was keeping me deep and when I did come to the net she had good passing shots."

Haberstroh held serve again to go ahead, 4-3. Macgill tried to serve and volley in the eighth game, but an erratic first serve prevented it, and Haberstroh broke her, making it 5-3.

Haberstroh won the final game when Macgill sent a backhand long.

Compared to the Har-Tru clay courts on which the earlier rounds were played, the indoor surface seemed to give Haberstroh a slight advantage, but the edge was not gained in the usual fashion.

Rarely did Haberstroh serve and volley, preferring to rally from the base line. Except for the sixth game of the second set, Macgill did the same.

"I thought I could outsteady her," Macgill said. "But she was pretty steady, too."

Macgill felt the outcome might have changed had they played the final on clay, where she had not lost more than three games in the four previous matches. In the semifinal, she defeated third-seeded Gail Falkenberg of Fredericksburg, Va., 6-1, 6-1. Haberstroh reached the final with a 7-5, 6-2 victory over Anne Geier of Silver Spring.

"It's easy to say now, but I think playing on clay might have changed things," Macgill said. "She does hit hard, so I think it would have slowed her putaways down. I could have gotten more balls."