Ivan Lendl, with an almost flawless serve and strong base line shots, eased past Tim Mayotte, 7-6 (7-4), 6-4, 6-1, yesterday to win the WCT Finals and the $150,000 first-place prize in Dallas.

Lendl, the world's No. 2 player, served nine aces and was aided by double faults by Mayotte.

The first set lasted more than an hour. Mayotte double faulted on the sixth point of the tie breaker.

Lendl's serve got stronger in the second set. He served six straight love games while Mayotte double faulted again at a critical time to lose his service in the ninth game. Mayotte hotly contested the out call, but umpire Leon Lipp wouldn't overrule it. Mayotte's service collapsed in the third set. Mayotte said Lendl "was serving so well I was just hanging on." . . .

In Nice, France, Henri Leconte defeated Victor Pecci, 6-4, 6-4, in the final of the $80,000 Nice Grand Prix . . .

Chris Evert Lloyd beat Gabriela Sabatini, 6-4, 6-0, to defend her title in the $200,000 Family Circle Magazine Cup at Hilton Head Island, S.C.

Sabatini, a 14-year-old who turned professional in January, was unseeded in the tournament. Last year, she was the youngest player in history to win a round at the U.S. Open. "There are a lot of players who looked good at 14 and fizzled out," Evert said. "I'm not going to predict anything. But she's certainly got all the shots." . . .

Top-seeded Claudia Borgiani of Maryland defeated third-seeded Sue Taylor of Duke, 4-6, 6-4, 6-4, to claim the individual crown during the eighth annual Atlantic Coast Conference women's tennis tournament at Wake Forest. Clemson took three of the six singles championships and two of the three doubles titles in earning the team championship. In the doubles final, third-seeded Pam Menne and Lisa Bobby of Clemson upset the top-seeded Maryland team of Borgiani and Jennifer Donecker, 4-6, 6-4, 6-3.