Geneva - World number five Alexander Zverev warmed up for the French Open by reaching only his second final of the season at the ATP event in Geneva with victory over Federico Delbonis on Friday.
The 22-year-old German came through a close match 7-5, 6-7 (6/8), 6-3 in two hours and 40 minutes to set up a Saturday final against Chile's Nicolas Jarry.
Zverev, who has never gone past the quarter-finals of a Grand Slam tournament, will open his Roland Garros campaign against Australian John Millman next week.
He let a 5-1 lead slip in the opening set in Switzerland, but fought back to take it in the 12th game.
Argentinian world number 84 Delbonis again pulled back a break of serve in the second set to win a tie-break and level the semi-final, but Zverev broke twice in the decider and sealed victory on his first match point.