Jack Lisowski pulled off an unexpected 6-4 win over Mark Selby to book his place in the final of the World Grand Prix against Judd Trump.
Lisowski had opened up a 5-1 lead following a run of half-century breaks and a clearance of 110 to appear on course for a comfortable victory.
However, Selby, winner of last week's Scottish Open, rallied as a break of 143 in frame seven, the highest of the tournament so far, sparked a comeback.
The world number four then built momentum of his own to edge the next two frames and cut the deficit back to 5-4.
Selby then seemed on course to level the match following a clearance of 52, but could not wrap up the frame as he over-cut a red when using the spider rest.
Lisowski, ranked 15th in the world, regained his composure after being allowed back on the table and cleared up with a 78 to seal a memorable win.