Qualifier Filip Krajinovic stunned world number 14 John Isner to reach Sunday's final of the Paris Masters.
Serb Krajinovic, playing in his first semi-final of the season, beat Isner 6-4 6-7 (2-7) 7-6 (7-5) to ensure the American cannot qualify for the season-ending ATP Tour Finals in London.
Krajinovic, ranked 77th in the world, will play another American - 16th seed Jack Sock - in the final.
Sock beat France's Julien Benneteau 7-5 6-2 in the second semi-final.
If he beats Krajinovic - playing in his first ATP Masters final - he will take the final qualifying spot for the Tour Finals from Spain's Pablo Carreno Busta.
Krajinovic, 25, received a walkover into the semi-final after Rafael Nadal withdrew on Friday with a knee injury.
Isner started strongly, forcing the Serb to save three break points in his opening service game, but Krajinovic broke Isner in the fifth game.
Big-serving Isner sent down 31 aces but Krajinovic held his nerve in the deciding set, before bursting into tears as he won the tie-break.