Bjorn Borg toiled for nearly 3 1/4 hours today before dispatching Ivan Lendl, 6-1, 4-6, 6-2, 3-6, 6-1, to win a record sixth French Open tennis title and his fourth in a row.

It was the closest Borg has come to being beaten here since he first won this clay court tournament in 1974. "It was the toughest final I have ever played here," Borg said.

The title was disputed in long rallies on the slow surface of the center court at Roland Garros Stadium before 16,000-17,000 fans. Lendl, 21, held his own in one rally after another until Borg prevailed in a rally of 34 strokes.

"Ivan has the perfect game for clay," said Borg, who was less accurate than usual and occasionally tried to force the pace by coming to the net, especially in the second set.

Borg won a first prize of $49,000 in becoming the first person to win the French title six times. Henri Cochet, one of France's legendary players, won this event five times between 1922 and 1932. But his first title came when this was a tournament for French players only.

The 1981 event proved to be an outstanding one for the young Czechoslovakians, Hana Mandlikova, 19, became the first Czech to win the women's title Saturday. Today, Lendl distinguished himself in defeat. Borg, who celebrated his 25th birthday Saturday, had not dropped a set on his way to the final.

"Ivan and I play similar games, and he was very strong from the back today," Borg said."His topspin was tiring, and he made the ball bounce awkwardly high."

The rallies were so grimly contested that the score often did not tell the whole story. From 1-1 in the first set, Borg won five straight games and lost only three points, yet this spell of tennis lasted 25 minutes and Lendl battled in some of the rallies for more than 40 strokes at a time.

The longest game of the match was the last one of the second set, when Lendl broke service and tied the match at a set each. Borg looked desperate. He saved four set points before Lendl suddenly quickened the tempo and Borg netted backhand.

Borg won the third set and Lendl fought back to two sets all.

In the second game of the final set, Borg hit one of the finest shots of the match -- a magnificent lob that left Lendl stranded at the net. It helped Borg to a service break and seemed to determine the outcome of the match.

Borg went to 4-0. Lendl made a final last effort and broke the champion's service for 1-4, but that was it as far as his challenge went.

In rallies that lasted 30 and 40 shots, Borg patiently saw the last two games through and kept his title.

In the women's doubles, Tanya Harford and Rosalyn Fairbanks upset Candy Reynolds and Paula Smith, 6-1, 6-3, in 1 hour and 10 minutes.

The players now move to England for two weeks of tournaments or practice on grass before Wimbledon begins June 22. Borg will be trying to win Wimbledon for a sixth straight time.