(Reuters) - Marathon man Pierre-Hugues Herbert of France delivered another Houdini-like escape to reach his first ATP World Tour final with a 3-6 7-6(5) 6-2 victory over Steve Johnson at the Winston-Salem Open in North Carolina on Friday.
The French qualifier, playing his eighth match in seven days, came from a set down against the 13th-seeded American and shrugged off an early break in the second to win a see-sawing semi-final in one hour 40 minutes.
Herbert, a doubles specialist who is ranked 140th in the singles, broke Johnson's serve twice in the third set and powered down 19 aces during the match to reach the final.
"I'm taking every day step by step, point by point, and trying not to think," Herbert, who needed almost two hours to beat Spaniard Pablo Carreno-Busta 4-6 7-6(5) 6-2 in the quarters, told reporters.
"Maybe that's why I'm capable of being there (in the final). I cannot believe it, really. I'm really tired."
The 49th-ranked Johnson had benefited from a walkover to reach the last four after Taiwan's Lu Yen-Hsun withdrew from their quarter-final on Thursday because of a back injury.
Herbert, a 24-year-old from Alsace, will face either second-seeded South African Kevin Anderson or unseeded Tunisian Malek Jaziri in Saturday's final at the Wake Forest Tennis Center.
Wild card Anderson and Jaziri were scheduled to play their semi-final later on Friday.
Herbert is poised to become the first qualifier to win an ATP World Tour title after playing nine matches since Spaniard Roberto Carretero triumphed in Hamburg in 1996.
The Frenchman is the eighth qualifier to reach an ATP World Tour final this year.
(Reporting by Mark Lamport-Stokes in Los Angeles; Editing by Frank Pingue)