Mirim Lee made a sensational start to the Women's British Open at Woburn with a record-equalling round of 62, then claimed she still had room for improvement.
Low scoring had been anticipated on the Marquess Course, but Lee opened up a three-stroke lead with her magnificent first round.
The 25-year-old South Korean, whose previous best finish at a major came when she finished tied-fourth at this year's Women's PGA Championship, birdied eight of the first 11 holes - including five in succession from the seventh - before picking up further shots on the 14th and 17th.
Yet Lee insisted her performance on Thursday was not faultless.
"It was probably one of my best ever rounds, although I still had some errant shots," she was quoted as saying by the Ladies European Tour website.
"I played every hole in a similar fashion, hitting fairways and greens."
Lee's nearest rival at the end of day one was Ariya Jutanugarn of Thailand, who went round in 65 to sit one clear of Shanshan Feng.
Stacy Lewis, the champion of this event in 2013, was also bogey-free in her 67, but world number one Lydia Ko would already appear to have too much to do after opening with a 74.
"Nothing was really that great," said Ko. "My short game wasn't that great to cover up for the missed shots and when I did hit it close, the putts didn't go in.
"When that's the case, you're not going to shoot a low score. But hopefully a few more putts drop tomorrow [Friday]. I've just got to stay positive."