New York - Five-time champion Roger Federer eased into the second round of the US Open on Tuesday, beating Japan's Yoshihito Nishioka 6-2, 6-2, 6-4.
The Swiss great, seeded second at Flushing Meadows behind defending champion and world number one Rafael Nadal, improved his perfect record in US Open first-round matches with his 18th win in 18 attempts.
As the opening attraction of the night session on Arthur Ashe Stadium, Federer escaped the worst of hot, humid conditions that punished players earlier in the day.
Nor did he meet much resistance from Nishioka, who was ranked 58th in the world last March before tearing a left knee ligament and sliding out of the top 150.
After rolling through the first two sets with the loss of just four games, Federer cruised to a 4-0 lead in the third. Up 5-1, he was unable to close out the match against Nishioka's serve, and then was broken on his first attempt to serve it out himself.
Federer, who claimed is 20th Grand Slam title at the Australian Open in January, would put the match away two games later, finally sealing the win with a service winner.
"I'm very happy to be back in New York healthy," said Federer, who claimed five straight US Open titles from 2004-2008 but missed the 2016 edition and only made it to the quarter-finals last year.
He next faces France's Benoit Paire, a 7-6 (8/6), 3-6, 7-5, 7-6 (7/5) winner over Austrian qualifier Dennis Novak.
US Open results on Tuesday, the second day of the 2018 tournament at Flushing Meadows (x denotes seeded player):
Men
First round
Marin Cilic (CRO x7) bt Marius Copil (ROM) 7-5, 6-1, 1-1 - retired
Hubert Hurkacz (POL) bt Stefano Travaglia (ITA) 6-2, 2-6, 7-6 (8/6), 3-0 - retired
Alex De Minaur (AUS) bt Taro Daniel (JPN) 6-0, 6-1, 6-2
Frances Tiafoe (USA) bt Adrian Mannarino (FRA x29) 6-1, 6-4, 4-6, 6-4
Julien Benneteau (FRA) bt Marco Cecchinato (ITA x22) 2-6, 7-6 (7/5), 6-3, 6-4
Jan-Lennard Struff (GER) bt Tim Smyczek (USA) 7-6 (7/2), 6-4, 6-3
Robin Haase (NED) bt Mackenzie McDonald (USA) 4-6, 4-6, 6-3, 6-1, 6-3
David Goffin (BEL x10) bt Federico Gaio (ITA) 6-2, 6-4, 7-6 (7/5)
Diego Schwartzman (ARG x13) bt Federico Delbonis (ARG) 6-2, 7-6 (8/6), 6-2
Jaume Munar (ESP) bt Ruben Bemelmans (BEL) 5-7, 6-3, 7-6 (7/3), 2-6, 6-1
Gael Monfils (FRA) bt Facundo Bagnis (ARG) 7-6 (7/4), 3-6, 6-0, 6-0
Kei Nishikori (JPN x21) bt Maximilian Marterer (GER) 6-2, 6-2, 6-3
Matthew Ebden (AUS) bt Filip Krajinovic (SRB x32) 7-6 (7/1), 6-7 (5/7), 4-6, 6-1, 4-1 - retired
Philipp Kohlschreiber (GER) bt Yannick Hanfmann (GER) 7-6 (7/3), 5-7, 6-4, 6-4
Nicolas Mahut (FRA) bt Corentin Moutet (FRA) 6-2, 7-5, 5-7, 6-4
Alexander Zverev (GER x4) bt Peter Polansky (CAN) 6-2, 6-1, 6-2
Novak Djokovic (SRB x6) bt Marton Fucsovics (HUN) 6-3, 3-6, 6-4, 6-0
Tennys Sandgren (USA) bt Viktor Troicki (SRB) 6-3, 6-4, 6-2
Laslo Djere (SRB) bt Leonardo Mayer (ARG) 6-4, 6-4, 4-6, 2-1 - retired
Richard Gasquet (FRA x26) bt Yuichi Sugita (JPN) 6-3, 6-1, 6-3
Lucas Pouille (FRA x17) bt Yannick Maden (GER) 7-6 (8/6), 6-2, 7-5
Marcos Baghdatis (CYP) bt Mikhail Youzhny (RUS) 6-4, 6-4, 2-6, 3-1 - retired
Joao Sousa (POR) bt Marcel Granollers (ESP) 6-2, 6-2, 6-3
Pablo Carreno-Busta (ESP x12) bt Malek Jaziri (TUN) 7-5, 6-2, 6-2
Fabio Fognini (ITA x14) bt Michael Mmoh (USA) 4-6, 6-2, 6-4, 7-6 (7/4)
John Millman (AUS) bt Jenson Brooksby (USA) 6-4, 6-2, 6-0
Mikhail Kukushkin (KAZ) bt Noah Rubin (USA) 6-3, 6-1, 4-6, 7-6 (7/3)
Chung Hyeon (KOR x23) bt Ricardas Berankis (LTU) 4-6, 7-6 (8/6), 6-0, 2-0 - retired
Nick Kyrgios (AUS x30) bt Radu Albot (MDA) 7-5, 2-6, 6-4, 6-2
Pierre-Hugues Herbert (FRA) bt Yuki Bhambri (IND) 6-3, 7-6 (7/3), 7-5
Benoit Paire (FRA) bt Dennis Novak (AUT) 7-6 (8/6), 3-6, 7-5, 7-6 (7/5)
Roger Federer (SUI x2) bt Yoshihito Nishioka (JPN) 6-2, 6-2, 6-4
Women
First round
Caroline Garcia (FRA x6) bt Johanna Konta (GBR) 6-2, 6-2
Monica Puig (PUR) bt Stefanie Voegele (SUI) 6-0, 6-0
Kristina Mladenovic (FRA) bt Tamara Zidansek (SLO) 6-0, 6-3
Carla Suarez Navarro (ESP x30) bt Nicole Gibbs (USA) 5-7, 6-3, 6-4
Maria Sharapova (RUS x22) bt Patty Schnyder (SUI) 6-2, 7-6 (8/6)
Sorana Cirstea (ROU) bt Alison Riske (USA) 6-3, 3-6, 7-5
Taylor Townsend (USA) bt Amanda Anisimova (USA) 3-6, 6-4, 6-3
Jelena Ostapenko (LAT x10) bt Andrea Petkovic (GER) 6-4, 4-6, 7-5
Madison Keys (USA x14) bt Pauline Parmentier (FRA) 6-4, 6-4
Bernarda Pera (USA) bt Yulia Putintseva (KAZ) 7-6 (8/6), 6-4
Aleksandra Krunic (SRB) bt Timea Bacsinszky (SUI) 6-2, 3-6, 6-0
Kirsten Flipkens (BEL) bt CoCo Vandeweghe (USA x24) 6-3, 7-6 (7/3)
Dominika Cibulkova (SVK x29) bt Arantxa Rus (NED) 4-6, 6-2, 6-3
Hsieh Su-Wei (TPE) bt Ekaterina Alexandrova (RUS) 6-3, 4-6, 6-3
Johanna Larsson (SWE) bt Alize Cornet (FRA) 4-6, 6-3, 6-2
Angelique Kerber (GER x4) bt Margarita Gasparyan (RUS) 7-6 (7/5), 6-3
Petra Kvitova (CZE x5) bt Yanina Wickmayer (BEL) 6-1, 6-4
Wang Yafan (CHN) bt Anna Karolina Schmiedlova (SVK) 6-1, 3-6, 6-4
Vera Zvonareva (RUS) bt Anna Blinkova (RUS) 6-2, 6-7 (6/8), 7-5
Aryna Sabalenka (BLR x26) bt Danielle Collins (USA) 6-0, 4-6, 6-4
Naomi Osaka (JPN x20) bt Laura Siegemund (GER) 6-3, 6-2
Julia Glushko (ISR) bt Monica Niculescu (ROU) 3-6, 7-5, 6-4
Aliaksandra Sasnovich (BLR) bt Belinda Bencic (SUI) 2-6, 6-1, 6-2
Darya Kasatkina (RUS x11) bt Timea Babos (HUN) 6-4, 5-7, 6-4
Kiki Bertens (NED x13) bt Kristyna Plyskova (CZE) 6-0, 7-5
Francesca Di Lorenzo (USA) bt Christina McHale (USA) 6-1, 7-6 (7/1)
Eugenie Bouchard (CAN) bt Harmony Tan (FRA) 6-3, 6-1
Marketa Vondrousova (CZE) bt Mona Barthel (GER) 6-1, 6-4
Katerina Siniakova (CZE) bt Anett Kontaveit (EST x28) 6-7 (3/7), 6-3, 7-5
Ajla Tomljanovic (AUS) bt Lizette Cabrera (AUS) 6-4, 6-1
Lesia Tsurenko (UKR) bt Alison Van Uytvanck (BEL) 6-3, 6-2
Caroline Wozniacki (DEN x2) bt Samantha Stosur (AUS) 6-3, 6-2