Her return was regarded by many as a capricious notion. Something of a sideshow at the first Grand Slam of the year.
But when the great champion takes to the court for Sunday's mixed doubles final, in tandem with Leander Paes, she will be just two sets away from completing a most extraordinary record.
Not only will Navratilova become the oldest Grand Slam champion in the history of tennis, but victory at Melbourne Park will give her a clean sweep of all three titles -- singles, doubles and mixed -- at all four Grand Slams.
The Australian mixed doubles crown is the only major title missing from a career in which she has amassed 18 Grand Slam singles titles, 31 Grand Slam doubles titles and seven of the mixed variety.
Quite what is going through the naturalised American's mind now is anybody's guess.
Unusually for the media-savvy Navratilova, she declined a request for a news conference after the semi-final victory over defending champions Kevin Ullyett and Daniela Hantuchova.
DOUBLES ACUMEN
Triumph at 46 years and three months will see her eclipse Australian Norman Brookes, who won the 1924 men's doubles here aged one month younger, and she easily beats Margaret DuPont, who was 44 when she won the 1962 Wimbledon mixed doubles.
She owns three Wimbledon mixed titles, 1985 with Paul McNamee -- now Australian Open tournament director -- 1993 with Mark Woodforde and 1995 with Jonathan Stark.
She won the U.S. mixed in 1985 with Heinz Gunthardt and 1987 with Emilio Sanchez and collected the French in 1974 with Ivan Molina and '85 in tandem with Gunthardt.
When she lost to Jim Pugh and Jana Novotna in the final in Melbourne back in 1988, she could have been forgiven for thinking it was a set she would never complete.
But now, 15 years on, she stands on the verge of equalling the record of Australia's Margaret Court who, however, achieved the landmark before tennis became professional.
Trim and toned, Navratilova put in a performance of skill and professionalism on Friday, one which rolled back the years.
Certainly the defending champions had no answer to her and Paes's court craft and doubles acumen, the sentimental favourites running away with the semi-final 6-3, 6-1.
Once the muscular powerhouse of tennis, Navratilova now looks short and slight compared to the heavy-hitting giants of the modern game, but she has lost none of her guile and cunning around the net.
Volleying superbly and serving with great authority, Navratilova put herself one step away from a 39th Grand Slam doubles title.
The U.S-Indian duo face Australia's Todd Woodbridge and Greek Eleni Daniilidou in the final.
Navratilova quit tennis in 1994 but returned six years later to play occasional doubles.
If she is successful on Sunday, it will prove to be perhaps the best decision of her life.