Elena Baltacha launched a superb recovery to reach the third round of the Australian Open with a 2-6 6-3 6-1 win over Stephanie Cohen-Aloro.
The 21-year-old qualifier looked to be on her way out of the tournament when she dropped serve twice in a row to lose the first set.
But the gritty Briton fought back magnificently to take the second set before cruising through the third.
Baltacha is the first British woman to reach the third round in 14 years.
She now faces 15th seed Silvia Farina Elia, with the possibility of a fourth-round encounter against Maria Sharapova, although Baltacha insisted she was not yet considering the Wimbledon champion.
"Farina Elia is seeded and she's a good player," Baltacha told BBC Five Live.
"I'm just really delighted with the way I've played this week, picking up a lot of ranking points. I've got nothing to lose so we'll see what happens."
The British number one looked unlikely to emulate Clare Wood's 1991 run to the third round in Melbourne after a poor first set against Cohen-Aloro.
She began well by holding her holding her opening service game to love but it proved to be a false dawn.
An error-count of 22 proved costly as her French opponent claimed the first set with some ease.
But Baltacha cut out the errors in the second set and, after receiving a warning from the umpire for taking too long between points, broke Cohen-Aloro's serve in the sixth game.
Baltacha went on to fire her second ace of the match as she served out to take the set and level the match.
And, with the momentum firmly on her side, she breezed through the final set.