Macfie, a former England junior, could not afford the official hotel and found sleeping room in a local house only at the last moment. Ranked 80 in the world, she overcame Rebecca O'Callaghan, the world No 13, in straight games in the biggest surprise of the tournament so far.
She unleashed a sequence of marvellously creative attacks to outplay the experienced Irish No 1, 9-4, 9-5, 9-0. She now meets Australia's fifth-seeded Robyn Lambourne.
There was also a notable scalp for the England No 6, Fiona Geaves, who possessed too much match tightness for Danielle Drady, Australia's former world No 2, who has needed a year to recover from an Achilles injury.
Last year's British Open champion, Lisa Opie, continued her recovery from the injuries that threatened her career with a 9-1, 9-2, 9-4 win over Finland's Nina Taimiaho, which earned her a meeting with the top seed and defending champion, Susan Devoy.
Also through safely in the same half are the British national champion, Sue Wright, and England's fine new hope, Cassie Jackman, the world junior champion.
England's second-seeded former world champion, Martine Le Moignan, won 9-6, 9-1, 9-4 against one of the all-time greats, 37-year-old Vicki Cardwell, four times a former British Open champion.Reuse content