Justine Henin-Hardenne had a narrow escape on her way to beating Serbia's Jelena Jankovic in the US Open semi-finals on Friday.
Henin-Hardenne has now made all four Grand Slam finals this year
The 2003 champion, seeded second, came back from a set and a break down to win 4-6 6-4 6-0 in exactly two hours.
The Belgian struggled on serve but reeled off 10 straight games from the end of the second set on her way to a fourth Grand Slam final of 2006.
Henin-Hardenne will face third seed Maria Sharapova in Saturday's final.
"I came back from nowhere today," said Henin-Hardenne. "I feel lucky to be in the final."
Henin-Hardenne is the first woman to reach all four Grand Slam finals in a year since Martina Hingis in 1997.
It was a struggle for the world number two for the first two sets as her remodelled serve malfunctioned alarmingly against Jankovic.
That was the kind of match I would have lost a year or two years ago
She later revealed that an aching back was partly to blame for 12 double faults and six dropped service games in the first two sets.
Jankovic more than played her part, however, dictating play with her impressive backhand as she broke four times on her way to winning the first set.
When the Serbian had a point to lead by 5-2 in the second, it appeared a major shock was on the cards.
But Henin-Hardenne showed the fighting qualities that have taken her to the French Open title and Australian Open and Wimbledon finals already this year.
After Jankovic had a lengthy and apparently distracting argument with the umpire over a call, the 21-year-old failed to win another game.
"I was a bit nervous at the beginning of the match," said Henin-Hardenne.
"She did put a lot of pressure on me. I could feel she had a lot of motivation and I wasn't in a good rhythm.
"That was the kind of match I would have lost a year or two years ago."
Jankovic said: "I was on the top of my game. She didn't know what to do, I thought. I was dominating.
"I'm young, I'll learn from my mistakes. I have to keep my focus the whole time."
And asked about Henin-Hardenne's apparent back problem, she added: "I was looking at her and she was, 'Oh I have pain in my back', or whatever she was doing.
"Then, when she was winning, all of a sudden she's hitting the biggest serves ever. I'm like, 'Now your back doesn't hurt?'"