Cape Town - South Africa's Lloyd Harris reached a maiden final at ATP level after beating America's Tommy Paul in Adelaide on Friday.
The 22-year-old rising tennis star won 6-4, 6-7 (3/7), 6-3 against the world No 90 to book his spot in Saturday's showpiece match at the ATP 250-level event.
Harris, who made his way through qualifying in Adelaide, also notched impressive wins earlier in the week against Spain's world No 30 Pablo Carreno Busta (6-3, 6-3), Chile's world No 36 Christian Garin (7-6 (7/5), 3-6, 6-4) and Serbia's world No 40 Laslo Djere (7-6 (7/5), 6-3).
"To be honest, it doesn't seem real now," Harris said courtside on Friday. "It was a tough match for both of us, we were both nervous.
"I'm really, really happy with the win. I had to go for it when I was serving for the match, he was ready to make me play. I knew it would be tough to serve it out, I had to put everything I had into the end."
Harris fired 13 aces and broke serve four times, while losing his own serve twice.
In the final, Harris will play either second-seeded Russian Andrey Rublev or third-seeded Canadian Felix Auger-Aliassime.
Harris entered the match ranked 91st in the ATP rankings, but Friday's win has seen his ranking surge to a career-high 72.
The South African also performed admirably at the ATP Cup last week, losing a tight match 6-3, 6-7 (4/7), 3-6 to Serbia's Dusan Lajovic, beating Chile's Nicolas Jarry 6-4, 6-4, before going down to French veteran Gilles Simon 6-2, 2-6, 2-6.
Harris made great strides last year by qualifying for the main draws of all four Grand Slam events.
He also won his first Grand Slam match at the French Open when he defeated Czech qualifier Lukas Rosol 6-1, 4-6, 2-6, 6-1, 6-2 in a five-set classic at Roland Garros.
Next week, Harris will open his Australian Open campaign against 14th-seeded Argentine Diego Schwartzman.
Results on day six of the ATP-WTA Adelaide International at Memorial Drive:
Lloyd Harris (RSA) bt Tommy Paul (USA) 6-4, 6-7 (3/7), 6-3
Dayana Yastremska (UKR) bt Aryna Sabalenka (BLR x6) 6-4, 7-6 (7/4)