21-year-old Seb Korda, the son of 1998 Australian Open champion Petr Korda, battled past a stubborn fellow American Brandon Nakashima 4-3, 2-4, 1-4, 4-2, 4-2 to set up a final against Carlos Alcaraz in Next Gen Final in Turin.
It will be the first meeting between the two.
Top seed Carlos Alcaraz was in full control against the world number 111 Sebastian Baez in his semi-final beating him in straight sets 4-2, 4-1, 4-2 in the shortened version of the game, which precedes the ATP Masters beginning on Sunday
There are different rules for the Next Gen tournament, including on-court coaching, no-Ad scoring, medical timeout limits, and Hawk-Eye making all the line calls.
The most noticeable change is the shorter first-to-four set, with a tiebreaker at 3-3.
Both Korda and Alcaraz won all three of their round-robin group stage matches.