Second-ranked Ivan Lendl, refusing to be unnerved by John McEnroe's temper tantrums, defeated the American for the fourth straight time, 6-2, 3-6, 6-3, 6-3, tonight for the World Championship of Tennis title and the $150,000 first prize.

It took three hours for Lendl, the most successful player in the world this year, to defeat McEnroe, top-ranked and defending champion. Lendl, 22, thus increased his earnings since Jan. 1 to $948,250; he has won 80 of his last 82 matches.

Only two men, McEnroe and Bjorn Borg, have ever won more than $1 million on the tennis court in a single year. Lendl is almost certain to surpass that figure before the year is half over.

"The more times you can beat a player like John the more you feel like a champion," said Lendl.

Lendl leads McEnroe, 4-2, in career matches. Tonight, he served aggressively and had 13 aces.

"Ivan is obviously a devastating player," McEnroe said. "He has shown that this year by dominating the circuit. He played like a dominating player tonight and he deserved to win. Maybe next time I will play better."

The beginning of the end came for McEnroe in the third game of the fourth set, a give-and-take contest that went to deuce eight times before Lendl broke service with a backhand winner. McEnroe never recovered.

The other key came in the eighth game of the third set, when Lendl broke service.

After splitting the opening two sets, the players held serve through the first seven games of the third. But McEnroe blew a 40-15 lead in the eighth game and at break point Lendl made a great save of a ball along the sideline. McEnroe eventually hit the ball into the net to give the game to the Czech.

McEnroe, 23, failed in his bid to become the first player to win the WCT Finals three times, but not before he tried every trick he knew.

McEnroe, troubled by an erratic first serve, tried to rattle Lendl with gamesmanship in the first set.

Picking on linesman Mickey Martin after a call, McEnroe told referee Zeno Pfau he wouldn't play until Martin was removed.

McEnroe told Pfau: "He (Martin) made a mistake."

Pfau diplomatically placed Martin in another position.

McEnroe played on, but not without taking extra time to towel off, making Lendl wait. McEnroe also took issue with a fan in a courtside seat.

Lendl broke McEnroe in the third and seventh games with outstanding backhand winners to win that set.

Although the approximately 15,000 fans in Reunion Arena booed McEnroe in the first set, they forgave his early tantrum and rallied to his side when he broke Lendl's service for the first time in the second game of the second set. McEnroe, who last beat Lendl in the quarterfinals of the 1980 U.S. Open, ended the set with back-to-back aces.

The third set point ended with McEnroe crashing into a row of yellow carnations at the southeast end of the court as Lendl held service.