Andy Murray hardly broke sweat as he reached the Miami Masters fourth round, defeating Robert Kendrick 6-3 6-1.
Murray is 75 places above Kendrick in the world rankings
Kendrick staved off four break points early on but the mistakes soon crept in and Britain's world number 12 broke for 4-2 and served out the opener.
Murray converted his first break chance in the second as the American made more unforced errors and broke him twice more, completing victory in 61 minutes.
The Scot meets unseeded Frenchman Paul-Henri Mathieu next in Miami.
Murray, 19, moved well around the court and said he is nearing full fitness after twisting his ankle in last week's quarter-final against Tommy Haas at Indian Wells.
I felt pretty good and served consistently
"I hurt myself against Haas and woke up afterwards aching and bruised," said Murray.
"But I felt pretty good today. I was a little bit nervous about my hip and ankle in my first match here but I feel much better now.
"I served pretty consistently. I felt when I was in the point I would be more consistent."
Murray showed touches of class against Kendrick, combining drop-shots, lobs and fierce returns from the baseline to leave the world 87 reeling.
But the British number one did not really need to be at his best against the American, who only sneaked into the tournament when Lleyton Hewitt withdrew with a back problem.
Murray is back in action on Tuesday and is expecting a much tougher contest against Mathieu, who saw off fifth seed Fernando Gonzalez 6-3 7-6.
"Mathieu can be one of the best players in the world when he is on form," he said.
World number two Rafael Nadal, who Murray is seeded to meet in the semi-finals, was given a walkover into the next round when his opponent Olivier Rochus pulled out with a foot injury.
Third seed Andy Roddick, who has yet to lose his serve in two matches, beat 32nd seed Gilles Simon 6-4 6-4.
Serbia's Novak Djokovic, who ended Murray's run in Indian Wells, also went through to the fourth round with a 6-4 6-1 win over Michael Llodra.
It was also straightforward for fourth seed Nikolay Davydenko, who swept aside Germany's Simon Greul 6-4 6-0 in his second round match.
Murray's older brother Jamie was knocked out in the first round of the men's doubles in Miami on Sunday.
He and American Eric Butorac had a tough draw against top seeds Jonas Bjorkman and Max Mirnyi and lost 7-5 6-0.