Trump ended the first session at the Baihu Media Broadcasting Centre with a break of 97 to take a 5-3 lead during a thoroughly engrossing first session.
'The Ace In The Pack' has not lost to Selby in four years, and Trump earned a return to the world number one spot on Thursday after his last 16 win over Joe Perry.
Trump closes on 12th ranking title with 12th century in China
Selby would have fancied a lead himself when he led 3-1, but in the best of 17 frames, it was Trump who held the advantage in the first semi-final in China after winning three frames in a row.
But having led by two frames, the world number six headed into the second session somewhat exasperated and with work to do to turn things around against a player who has enjoyed handsome victories over him in each of their previous three meetings.
Mark Selby will wonder how he allowed his 3-1 lead to slip
Image credit: Getty Images
Jump immediately set about extending his lead at the start of the second session as a ninth century of the week (108) left Selby with an increasingly more difficult task.
Having moved to within three frames of the final, the world champion made it 7-3 with a scintillating break of 97 that just fell short of another century after missing a yellow.
There was no stopping Trump, however, as another century left Selby resigned to defeat - and while the three-times World Snooker Champion took advantage of a missed red to steal a frame, a rampant Trump sealed the win after a mid-session break with a 72 to book his spot in the final.
Close friends Shaun Murphy and Mark Allen will contest the other semi-final at 7.55am UK time on Saturday, live on Eurosport.
Trump demolishes Murphy to win International Championship