Defending champion Andy Murray beat Germany’s Florian Mayer 7-6 (7-2), 6-2, 6-2, to reach the last 16 of the US Open.
The world number three overcame a sluggish start to see off the 47th seed in one hour 59 minutes on a steamy afternoon at the Arthur Ashe Stadium.
Murray lost three break points amid a flurry of challenges and overrules in the opening game as he was unable to stamp his authority on the contest.
However, Mayer was made to pay in the tie-break when the 26-year-old Wimbledon champion broke on the first point and hit an ace on the second, providing him the leverage to control the game at 4-0.
He went on to claim the set after 54 minutes with a blistering forehand winner at 5-1.
“It was very, very humid. I was struggling with my breathing for most of the match,” said Murray.
“With the way that he plays, it was a tough match, especially the beginning.
“But I started the second set well, started hitting the ball a little bit cleaner, was more aggressive after that and finished it well.”
Murray will face Uzbekistan’s Denis Istomin on Tuesday in the fourth round.