Harriet Dart rallied from a set down at Indian Wells to defeat former world No 3 Elina Svitolina and progress to the third round for the first time in her career
Dart was broken four times in the opening set by the 12th-seeded Ukrainian at the BNP Paribas before steading herself in the second.
The British No 3, ranked 122nd in the world, managed to break Svitolina three times consecutively to lead 5-3 then smashed a crucial ace to claim the set.
Dart rushed out to a 3-0 lead in the decider but Svitolina scraped back some points before the match - which took two hours and 17 minutes - finished 2-6 6-3 6-3 in the qualifier's favour.
Kaia Kanepi will face Dart next after the Estonian needed just 81 minutes to upset 22nd seed Belinda Bencic 6-4 6-3.
Liam Broady, meanwhile, failed to progress past the first round despite taking a set off Miomir Kecmanovic.
The Serbian has now won both his encounters against Broady following the 6-4 4-6 6-4 encounter in California on Friday.
