Cape Town - South Africa's Lloyd Harris has advanced to the round of 16 at the Delray Beach Open in Florida after beating Darian King of Barbados on Monday evening.
The 21-year-old prevailed 7-6 (7/1), 6-3 in the encounter.
"Its all pretty new, but I’'m happy (with) my game," Harris told the tournament's official website.
"I've been playing well and with a lot of confidence. The last six months, I've been playing, I'd say, my best tennis. . . . If I play good, I believe I can beat anyone."
Harris will face qualifier Daniel Evans of Great Britain in his last 16 clash on Wednesday at 21:30 SA time.
Evans defeated the defending champion Frances Tiafoe, who made an early exit with a 3-6, 7-6(1), 7-5 upset.
Harris, who broke into top 100 in the world, is currently working with two-time Australian Open semi-finalist Wayne Ferreira.
Results from Monday's matches at the ATP Delray Beach Open (x denotes seed):
Lukas Lacko (SVK) bt Yosuke Watanuki (JPN) 6-4, 6-4
Denis Istomin (UZB) bt Feliciano Lopez (ESP) 7-6 (7/5), 6-2
Lloyd Harris (RSA) bt Darian King (BAR) 7-6 (7/1), 6-3
Nick Kyrgios (AUS) bt John Millman (AUS x5) 6-4, 6-7 (1/7), 7-6 (7/3)
Results from Tuesday's matches at the ATP Delray Beach Open (x denotes seeding):
Guillermo Garcia-Lopez (ESP) bt Jared Donaldson (USA) 2-6, 6-3, 6-3
Mackenzie McDonald (USA) bt Taylor Fritz (USA x7) 3-6, 6-4, 6-3
Radu Albot (MDA) bt Ivo Karlovic (CRO) 7-6 (7/2), 6-4
Jordan Thompson (AUS) bt Marcel Granollers (ESP) 7-5, 6-1
Steve Johnson (USA x4) bt Jason Jung (TPE) 7-6 (7/3), 6-4
Paolo Lorenzi (ITA) bt Tim Smyczek (USA) 7-5, 6-3
Andreas Seppi (ITA x6) bt Bernard Tomic (AUS) 6-4, 7-5
Adrian Mannarino (FRA x8) bt Brayden Schnur (CAN) 6-2, 6-2
John Isner (USA x2) bt Peter Polansky (CAN) 6-3, 7-6 (7/4)
Reilly Opelka (USA) bt Tennys Sandgren (USA) 6-4, 6-0
Daniel Evans (GBR) bt Frances Tiafoe (USA x3) 3-6, 7-6 (7/1), 7-5
Juan Martin Del Potro (ARG x1) bt Yoshihito Nishioka (JPN) 6-3, 7-5