The Welshman will now face first-time finalist Zhao Xintong of China in the best of 35-frame showpiece match at Sheffield’s Crucible Theatre, England on Sunday and Monday.
Williams fought back from a four-frame deficit against England’s Trump, the world number one, to end Friday’s play against the 2019 world champion all square at 8-8.
But the 50-year-old Williams pulled clear on Saturday and was on the brink of victory at 16-12 ahead.
Trump, however, closed to within two frames after the 35-year-old extended the record he set earlier in the tournament for most centuries in a season with his 107th three-figure break of a campaign where he has won four ranking titles.
Nevertheless Williams, after Trump missed a cut-back on the black, held his nerve in the 31st frame, with a break of 123 sealing victory as he reached the world final for the first time since the third of his Crucible triumphs in 2018. (AFP)
