Britain's Andy Murray defeated Chinese wildcard Ye Cong Mo to win his opening match of the Zhuhai Championships.
The former world number one battled "very humid" conditions to beat Mo 7-5 6-3 and reach the last 16.
"It was a very, very fast court," he said.
"My opponent played a solid level at the beginning of the match and pushed me while I was trying to adjust to the conditions.
"Once I managed to get ahead at the beginning of the second set, I felt a bit more comfortable but it wasn't easy and a lot of the players have said the same thing.