NEW YORK, Sept 1 (Reuters) - Defending champion Andy Murray sailed along after winning a first-set tiebreaker to defeat Florian Mayer of Germany in straight sets and book a berth in the fourth round of the U.S. Open on Sunday.
Murray began to find the range in the tiebreak, winning it decisively at 7-2 and carrying on to a 7-6(2) 6-2 6-2 victory in hot, humid conditions on Arthur Ashe Stadium court.
"Very tough conditions today," third seed Murray said after eliminating Mayer, ranked 47th.
"He's a very tricky opponent, plays a lot of strange shots. Takes your timing away and tough to get your rhythm, so I'm really glad to come through in three sets."
Steamy conditions led the Scotsman to play without his trademark baseball cap and apply ice packs on his legs during changeovers.
"It cooled down a bit toward the end, but at the end of the first set and in the second set it was extremely hot," he said.
Wimbledon champion Murray will play either 20th seed Andreas Seppi of Italy or Denis Istomin of Uzbekistan for a place in the quarter-finals. (Reporting by Larry Fine, Editing by Gene Cherry)