Un-Nooh came from 4-2 down to edge out David Gilbert 5-4, reaching the sixth ranking event semi-final of his career. The 34-year-old from Bangkok won his first ranking title last season at the one frame Shoot Out, but has lost all four semi-finals he has played over a longer format.
From 2-1 down, Gilbert won three frames in a row with breaks of 100, 55 and 62 to lead 4-2. But world number 37 Un-Nooh, the fastest player on the tour with an average shot time of 16.6 seconds, reeled off the last three frames in 37 minutes with runs of 77, 66 and 96.
World number nine Wilson saw off China’s Zhou Yuelong 5-3 to reach his 12th ranking semi-final. He is aiming for his fourth career ranking title.
From 1-0 down, Kettering’s Wilson won three frames in a row with top runs of 119 and 64. Zhou took two of the next three to leave the score at 4-3, before Wilson sealed victory in the eighth with breaks of 52 and 33.
In the second session of quarter-final action on Friday, Judd Trump takes on Michael Holt and John Higgins plays Stuart Bingham.
The semi-finals are on Saturday followed by the final on Sunday, with a top prize of £150,000 up for grabs.