Britain's Emma Raducanu overcame a late wobble to beat Japan's Moyuka Uchijima in the first round of the Korea Open in Seoul.
Raducanu, 19, double-faulted on match point when holding a 5-0 lead in the second set before winning 6-2 6-4.
Victory set up a last-16 match against Belgium's Yanina Wickmayer.
Raducanu had been 10th in the world rankings in August but has dropped to 77th after losing in the US Open first round earlier this month.
Uchijima, 21, who has never played a Grand Slam match and is 126th in the rankings, won four games in a row in the second set to peg Raducanu back to 5-4 before the Briton served out the victory after one hour 18 minutes.
Wickmayer, 32, is a former world number 12 but is now 460th in the world rankings. She returned from maternity leave earlier this year after giving birth to her first child, Luana, in April 2021.