Serena Williams admitted she choked as she narrowly avoided an embarrassing first-round defeat in her Australian Open title defence with a battling 6-3, 6-7, 6-2 win over unseeded Chinese player Li Na on Monday.
"Everyone chokes, I choked today," a relieved Williams told Australian television after she avoided joining her sister Venus as a first-round casualty.
Williams returned to Melbourne with question marks over her fitness after knee and ankle injuries forced a long lay-off last year and she almost became only the second defending Australian champion to lose in the opening round.
Jennifer Capriati was the first in 2003.
Seeded 13th after her ranking plummeted when she played just 23 matches after winning in Melbourne last year, Williams served for the match in the 10th game of the second set.
But two consecutive double faults handed Li a crucial service break that turned the course of the match.
Li, who reached the third round in her first grand slam tournament in Melbourne last year, then kept Williams running around the court and was able to force a tiebreaker, which the Chinese woman dominated 7-1.
The pair traded service breaks at the start of the deciding set before a relieved Williams snapped back into gear, breaking Li's service twice more before closing out the match after 126 minutes on Rod Laver Arena.
"I just lost it basically, I didn't do what I needed to do," Williams said of her mid-match slump.
But it was an unconvincing performance and doubts will linger over her fitness after a match in which she hit 45 unforced errors to Li's 58.
Williams remains on track for a fourth-round showdown with Russian fourth seed Maria Sharapova.
She beat Sharapova in an epic semi-final last year after the Russian held three match points and served for the match in the second and third sets before Williams triumphed 2-6 7-5 8-6.
Williams' oldest sister Venus, the 10th seed, was beaten 2-6 6-0 9-7 by little-known Bulgarian teenager Tszvetana Pironkova earlier on Monday.
