Michael Smith and Gerwyn Price will meet in a blockbuster semi-final clash at the World Grand Prix on Saturday.World number one Smith eased past UK Open champion Andrew Gilding to make the last four for the first time at this double-in-double-out tournament in Leicester.Smith, who has never previously got past the second round, won 3-0 with an average of 87.69.Price is the 2020 champion and looked in ominous form as he annihilated German Martin Schindler.The Welshman dropped just one leg in his 3-0 success, averaging 90.73.Luke Humphries will play Joe Cullen in the other semi-final after completing a monumental comeback against Peter Wright.Humphries looked dead and buried when he trailed 2-0 to Wright, but picked himself up off the canvas and won the final three sets.Cullen was the last man to seal his place in the last four, winning a deciding set against Chris Dobey in style as he checked out on 121.Dobey had knocked Michael van Gerwen out on Thursday but could not follow it up.Cullen, into his first semi-final, told Sky Sports: "If I am being completely honest, if that hadn't gone in I think I would have lost the game.