Elena Baltacha has claimed the best win of her career with a second-round victory over China's seventh seed Li Na in Indian Wells.
The British number one is currently in the form of her life, having claimed a few notable scalps over the past few months, and she continued her excellent season with a three-set victory over the world number 10.
The 26-year-old had already won two qualifying matches and a first-round clash with US wildcard Alexa Glatch, but she showed no signs of fatigue with a 7-6 (10-8) 2-6 7-6 (9-7) victory in a marathon match which lasted nearly three hours.
Having lost the second set and taken the third to a tie-break, it looked as though the Ukrainian-born Brit would crash out of the tournament, as she slipped 5-1 behind in the 'breaker.
However she hit back, winning eight of the next 10 points to seal the first win of her career over a top-ten ranked player.
Baltacha will now play Aussie wildcard Alicia Molik in the third round and she admitted that she had to dig deep for the win after her opponent upped her game at the business end of the match.
"As the tiebreak started, she just came out with unbelievable stuff," she said. "I think she hit four backhand winners down the line. I thought, 'OK, yeah, that's why you're top 10. I understand.'
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But then at 5-1, I went into the zone and I felt really strong and I just fought my heart out.
"I think sometimes with the top players, the best time to play them is when they haven't played a match. They haven't experienced the conditions, they haven't experienced the court, and it can be a bit tricky for them."