The 30-year-old from Samut Prakan now enters the semi-finals in Cheltenham, England after three consecutive wins against former world champions.
Noppon, ranked 33 in the world, qualified for the last four by beating Welshman Williams 93-0, 70-0, 38-81, 34-90, 79-0, 41-70, 72-25, and 78-67.
Nicknamed “Mu Paknam”, Noppon beat four-time world champion Mark Selby in the first round and seven-time world champion Ronnie O'Sullivan in the second round.
The Thai ace faces another daunting match against world No 5 Mark Allen from Northern Ireland on Friday night for a place in the final.
Noppon has only won once in four previous encounters with the Northern Irishman, at the China Championship in 2019. The last time they met, three months ago at the British Open, Allen destroyed Noppon 6-1.