Cape Town - South Africa's Lloyd Harris suffered a first round defeat at the US Open in Flushing Meadows, New York on Tuesday.
The world No 100 lost in straight sets - 7-5, 7-6 (7/5), 7-6 (7/3) - to Belarusian qualifier Egor Gerasimov.
It was three tight sets but Harris just made too many errors at crucial junctures. The South African served 14 aces but an uncharacteristic eight double faults proved costly.
Harris also hit more winners (50) than his 129th-ranked opponent (37) but 46 unforced errors compared to the 37 of Gerasimov made a difference.
Despite the defeat, Harris has made great strides this year by qualifying for the main draws of all the 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.
The 22-year-old had a career-high ranking of 82 last month.
He was the only South African participating in the main draw of the men's singles, following the withdrawal due to a knee injury of 2017 finalist Kevin Anderson.
In the men's doubles, South Africa's Raven Klaasen and his New Zealand partner Michael Venus are expected to go deep into the tournament.
Klaasen and Venus are the third seeds and will face French duo Adrian Mannarino and Gilles Simon in the first round on Wednesday.
Meanwhile, in the wheelchair event that starts on September 5, Kgothatso Montjane will again be featuring.
Montjane, the first African wheelchair tennis player to play at all four Grand Slams, was also a semi-finalist in London and will eye another impressive showing.
Results from Tuesday's second day of the US Open tennis championships: (x denotes seed):
Men
First round
Andrey Rublev (RUS) bt Stefanos Tsitsipas (GRE x8) 6-4, 6-7 (5/7), 7-6 (9/7), 7-5
Gilles Simon (FRA) bt Bjorn Fratangelo (USA) 5-7, 7-5, 7-5, 7-5
Matteo Berrettini (ITA x24) bt Richard Gasquet (FRA) 6-4, 6-3, 2-6, 6-2
Jordan Thompson (AUS) bt Joao Sousa (POR) 6-3, 6-2, 6-4
Alexei Popyrin (AUS) bt Federico Del Bonis (ARG) 6-1, 7-5, 7-6 (7/5)
Mikhail Kukushkin (KAZ) bt Roberto Bautista Agut (ESP x10) 3-6, 6-1, 6-4, 3-6, 6-3
Gael Monfils (FRA x13) bt Albert Ramos (ESP) 7-6 (7/2), 6-4, 6-3
Marius Copil (ROU) bt Ugo Humbert (FRA) 6-3, 5-7, 7-6 (13/11), 4-6, 6-1
Denis Shapovalov (CAN) bt Felix Auger-Aliassime (CAN x18) 6-1, 6-1, 6-4
Pablo Andujar (ESP) bt Kyle Edmund (GBR x30) 3-6, 7-6 (7/1), 7-5, 5-7, 6-2
Lorenzo Sonego (ITA) bt Marcel Granollers (ESP) 6-3, 6-4, 6-4
Alexander Bublik (KAZ) bt Santiago Giraldo (COL) 2-6, 6-0, 7-5, 3-6, 6-4
Thomas Fabbiano (ITA) bt Dominic Thiem (AUT x4) 6-4, 3-6, 6-3, 6-2
Alexander Zverev (GER x6) bt Radu Albot (MDA) 6-1, 6-3, 3-6, 4-6, 6-2
Frances Tiafoe (USA) bt Ivo Karlovic (CRO) 6-2, 6-3, 1-2, retired
Aljaz Bedene (SLO) bt Jozef Kovalík (SVK) 6-3, 6-4, 7-5
Benoît Paire (FRA x29) bt Brayden Schnur (CAN) 6-2, 6-4, 6-4
Diego Schwartzman (ARG x20) bt Robin Haase (NED) 6-3, 7-6 (8/6), 6-0
Egor Gerasimov (BLR) bt Lloyd Harris (RSA) 7-5, 7-6 (7/5), 7-6 (7/3)
Tennys Sandgren (USA) bt Jo-Wilfried Tsonga (FRA) 1-6, 6-7 (2/7), 6-4, 7-6 (7/5), 7-5
Vasek Pospisil (CAN) bt Karen Khachanov (RUS x9) 4-6, 7-5, 7-5, 4-6, 6-3
John Isner (USA x14) bt Guillermo Garcia-Lopez (ESP) 6-3, 6-4, 6-4
Jan-Lennard Struff (GER) bt Casper Ruud (NOR) 6-4, 6-4, 6-2
Cedrik-Marcel Stebe (GER) bt Filip Krajinovic (SRB) 6-3, 4-6, 6-4, 7-6 (8/6)
Marin Cilic (CRO x22) bt Martin Klizan (SVK) 6-3, 6-2, 7-6 (8/6)
Fernando Verdasco (ESP x32) bt Tobias Kamke (GER) 6-3, 3-6, 6-1, 6-2
Chung Hyeon (KOR) bt Ernesto Escobedo (USA) 3-6, 6-4, 6-7 (5/7), 6-4, 6-2
Thanasi Kokkinakis (AUS) bt Ilya Ivashka (BLR) 6-3, 7-6 (10/8), 6-7 (4/7), 6-2
Rafael Nadal (ESP x2) bt John Millman (AUS) 6-3, 6-2, 6-2
Antoine Hoang (FRA) bt Leonardo Mayer (ARG) 3-6, 6-2, 6-7 (6/8), 6-1, 6-3
Henri Laaksonen (SUI) bt Marco Cecchinato (ITA) 7-6 (7/3), 7-6 (8/6), 2-6, 3-6, 7-6 (7/2)
Nick Kyrgios (AUS x28) bt Steve Johnson (USA) 6-3, 7-6 (7/1), 6-4
Women
First round
Naomi Osaka (JPN x1) bt Anna Blinkova (RUS) 6-4, 6-7 (5/7), 6-2
Magda Linette (POL) bt Astra Sharma (AUS) 6-3, 6-4
Cori Gauff (USA) bt Anastasia Potapova (RUS) 3-6, 6-2, 6-4
Timea Babos (HUN) bt Carla Suarez Navarro (ESP x28) 6-2, 0-0, retired
Anett Kontaveit (EST x21) bt Sara Sorribes (ESP) 6-1, 6-1
Ajla Tomljanovic (AUS) bt Marie Bouzková (CZE) 1-6, 7-5, 6-1
Alize Cornet (FRA) bt Jessica Pegula (USA) 6-2, 6-3
Belinda Bencic (SUI x13) bt Mandy Minella (LUX) 6-3, 6-2
Kaia Kanepi (EST) bt Tatjana Maria (GER) 5-7, 7-6 (7/4), 6-3
Julia Görges (GER x26) bt Natalia Vikhlyantseva (RUS) 1-6, 6-1, 7-6 (7/1)
Francesca Di Lorenzo (USA) bt Veronika Kudermetova (RUS) 7-6 (7/4), 6-2
Anastasia Pavlyuchenkova (RUS) bt Pauline Parmentier (FRA) 6-1, 7-6 (7/2)
Kiki Bertens (NED x7) bt Paula Badosa (ESP) 6-4, 6-2
Simona Halep (ROU x4) bt Nicole Gibbs (USA) 6-3, 3-6, 6-2
Taylor Townsend (USA) bt Kateryna Kozlova (UKR) 3-6, 6-3, 6-2
Sorana Cirstea (ROU) bt Katerina Siniakova (CZE) 7-5, 6-2
Aliona Bolsova (ESP) bt Barbora Strycova (CZE x31) 6-3, 0-6, 6-1
Caroline Wozniacki (DEN x19) bt Wang Yafan (CHN) 1-6, 7-5, 6-3
Danielle Collins (USA) bt Polona Hercog (SLO) 6-3, 4-6, 6-4
Kirsten Flipkens (BEL) bt Wang Xiyu (CHN) 3-6, 6-2, 6-2
Bianca Andreescu (CAN x15) bt Katie Volynets (USA) 6-2, 6-4
Kristie Ahn (USA) bt Svetlana Kuznetsova (RUS) 7-5, 6-2
Jelena Ostapenko (LAT) bt Aleksandra Krunic (SRB) 6-3, 7-6 (9/7)
Alison Riske (USA) bt Garbine Muguruza (ESP x24) 2-6, 6-1, 6-3
Elise Mertens (BEL x25) bt Jil Teichmann (SUI) 6-2, 6-2
Kristyna Pliskova (CZE) bt Diane Parry (FRA) 6-4, 6-3
Andrea Petkovic (GER) bt Mihaela Buzarnescu (ROU) 6-3, 6-4
Petra Kvitova (CZE x6) bt Denisa Allertova (CZE) 6-2, 6-4
Donna Vekic (CRO x23) bt Richel Hogenkamp (NED) 7-6 (7/4), 6-3
Yulia Putintseva (KAZ) bt Madison Brengle (USA) 6-3, 6-3
Aryna Sabalenka (BLR x9) bt Victoria Azarenka (BLR) 3-6, 6-3, 6-4
Anna Kalinskaya (RUS) bt Sloane Stephens (USA x11) 6-3, 6-4