Evans, who had knocked out the third seed in the previous round, lost 9-15, 15-11, 15-6, 15-8 to the Australian 10th seed, Dan Jenson, in 64 minutes at the National Indoor Arena in Birmingham.
The 23-year-old, from Pontypool, started strongly and seemed on course for another remarkable win, but an extended rally which gave the Australian 8-9 in the second game seemed to drain Evans' energy and from that point Jenson had the upper hand.
Evans, who came through qualifying, had beaten the 11th seed, Del Harris, and then the third seed, Jonathon Power, to reach the last eight.
Victory took Jenson into a semi-final against the second seed and defending champion, Jansher Khan, who earlier removed Paul Johnson 15-11, 15-11, 17-15 in 59 minutes.
The defending champion has been troubled by a displaced kneecap and a cartilage tear, but insisted they are not bothering him at the moment. "I may have to have an operation eventually, but for the time being I've decided just to play on," he said.
In the women's British Open, Cassie Jackman cruised into the semi-finals. The 25-year-old world No 4 defeated the sixth-seeded German Sabine Schone 10-8, 9-6, 9-7 in 55 minutes.
She now plays the world champion Sarah Fitz-Gerald, of Australia, who beat Fiona Geaves 9-1, 9-6, 9-5 in only 35 minutes.Reuse content