It’s Last Stop on Navratilova’s Farewell Tour : Tennis: One of the sport’s greatest players will end 22-year career at Virginia Slims Championships.

Hers is a tennis career not likely to be glimpsed again, if not for its record 167 singles titles then surely for its 22 years in duration. In an era of teen-aged flameouts and injury-induced retirements, Martina Navratilova remains an enduring reminder that sheer will could join with emotion to create a potent athletic force.

But not for much longer. It will be with an abiding sense of closure that Navratilova begins her last tournament, the $3.5 million Virginia Slims Championships, which begin today at Madison Square Garden. The season-ending event and the Garden’s blue carpet have been a kind of home to Navratilova, who has made it to the finals in 12 of 16 singles competitions.

Navratilova, 38, has been such a lasting fixture on the women’s circuit that it has come to this: In the year she has chosen to retire, she witnessed the debut of the tour’s youngest player, Martina Hingis, who was optimistically named after the nine-time Wimbledon champion.

Navratilova, who began her career in 1973, is retiring because she says she’s getting old and eager to start the second half of her life, which, she expects, will have much to do with adventure and activism. Tennis now seems to be too limited a world. Navratilova’s competitive drive--always the spark to her tenacity--is flagging. Always ranked in the top five since 1975, Navratilova is now No. 6 and no longer expected to walk over her first-round opponents.

She’ll face Gabriela Sabatini Tuesday night. No matter the outcome, Navratilova will be honored after the match with a ceremony during which a retirement banner will be raised to the rafters of the Garden, where she has won 18 titles--seven singles and 11 doubles. The banner will be displayed during all tennis events in the arena.

Navratilova, a most sentimental athlete, will no doubt be carried by the sentiment of the New York crowd, which rooted against her early in her career at the U.S. Open, favoring the cool but inaccessible Chris Evert. The city’s rowdy fans warmed to Navratilova, whose unequaled power awed them and whose heart-on-her-sleeve openness created a rapport.

Indoors, the fans can be a factor.

“I’m looking forward to playing her, especially because it’s her last tournament,” Sabatini said. “But I’ll have to forget about all that when I’m on the court and just play my best.”

Ever the fighter, Navratilova yearns to end her career with a victory, but even reaching the final, as she did two weeks ago in Oakland, will be considered a triumph. The elite field brings together the top 16 players and eight doubles teams, and, as happens at the end of the tennis calender, the event’s subplots are about rankings.

Steffi Graf, the world’s top-ranked player, might not be in New York to defend her title. Graf is scheduled to meet Brenda Schultz, but a recurring back injury caused Graf to pull out of a tournament last week in Philadelphia and two other tour events since the U.S. Open. Graf practiced with Navratilova on Friday and said she would wait to decide if she could play.

That could affect the year-end rankings, especially if No. 2 Arantxa Sanchez Vicario continues to play well. Her first-round opponent is Julie Halard.