London - Kei Nishikori equalled Ai Sugiyama's record of four appearances in the last 16 of Wimbledon by a Japanese player on Saturday as he dismissed American journeyman Steve Johnson 6-4, 6-3, 6-2.
The 29-year-old 2014 US Open finalist, who recorded his 400th Tour level match win, will play the winner of the match between Germany's Jan-Lennard Struff and Kazakhstan's Mikhail Kukushkin for a place in the last eight.
Sugiyama reached the women's last 16 in 1996, 2003, 2004 and 2006.
Wimbledon results on Saturday (x denotes seeding):
Sam Querrey (USA) bt John Millman (AUS) 7-6 (7/3), 7-6 (10/8), 6-3
Tennys Sandgren (USA) bt Fabio Fognini (ITA x12) 6-3, 7-6 (14/12), 6-3
Rafael Nadal (ESP x3) bt Jo-Wilfried Tsonga (FRA) 6-2, 6-3, 6-2
Kei Nishikori (JPN x8) bt Steve Johnson (USA) 6-4, 6-3, 6-2
Ashleigh Barty (AUS x1) bt Harriet Dart (GBR) 6-1, 6-1
Alison Riske (USA) bt Belinda Bencic (SUI x13) 4-6, 6-4, 6-4
Serena Williams (USA x11) bt Julia Goerges (GER x18) 6-3, 6-4
Carla Suarez Navarro (ESP x30) bt Lauren Davis (USA) 6-3, 6-3
Barbora Strycova (CZE) bt Kiki Bertens (NED x4) 7-5, 6-1
Elise Mertens (BEL x21) bt Qiang Wang (CHN x15) 6-2, 6-7 (9/11), 6-4
Johanna Konta (GBR x19) bt Sloane Stephens (USA x9) 3-6, 6-4, 6-1
Petra Kvitova (CZE x6) bt Magda Linette (POL) 6-3, 6-2