Top seed Andrey Rublev brushed aside Brandon Nakashima in just over an hour to clinch a spot in the San Diego Open quarter-finals.
Rublev – the world number five – won 6-2 6-1 over local 20-year-old Nakashima at the ATP 250 tournament on Wednesday.
Nakashima claimed only two of 18 second serve points for the match, with Rublev breaking him six times and triumphing in one hour, two minutes midweek.
The result improves 2021 Australian Open quarter-finalist Rublev's record to 45-15 this calendar year.
Rublev will take on sixth seed Diego Schwartzman, who rallied to defeat Lloyd Harris 4-6 6-3 6-2 in San Diego.
Fifth seed Hubert Hurkacz moved into the next round with a 7-6 (7-2) 6-1 victory over Australian qualifier Alex Bolt.
Hurkacz will face Russian and 2021 Australian Open semi-finalist Aslan Karatsev in the round of 16.
Daniel Evans – the eighth seed – overcame former Wimbledon and US Open runner-up Kevin Anderson 7-6 (13-11) 7-5 after more than two hours on court.
Evans will meet countryman Cam Norrie next.