"We know each other's games pretty well, we practise a lot together," said Murray. "He hits the ball very flat and these courts were playing quick.
"I was struggling. He was making me feel pretty uncomfortable on the court with his style. I need to strike the ball better.
"My timing was off and I was leaving a lot of balls very short and allowing him to dictate some of the points. But hopefully it'll get better in the next round."
Murray made 24 winners and produced 27 unforced errors during his win over Berankis.