Andy Murray of Britain hits a return ball to Mikhail Youzhny of Russia at the Men's Cincinnati Open tennis tournament in Cincinnati, Ohio August 14, 2013. [Photo/Agencies]

They clashed in the finals of three of the last four grand slams with Djokovic coming out on top in Australia and Murray the winner at the US Open and Wimbledon.

Murray, who had a slow start to the hardcourt season with a third round loss in Montreal last week, arrived in Cincinnati eager to get in matches ahead of the August 26-Sept 9 US Open, where he will arrive as a defending grand slam champion for the first time.

The Cincinnati hardcourts proved a perfect spot to build some momentum and Youzhny the perfect opponent as the Wimbledon champion needed just 70 minutes to run his record to 4-0 against the overmatched Russian.

"I thought he made more mistakes than I'd expected," said Murray. "But he played yesterday and very different conditions today because it was cool on the court.

"I just wanted to try to play a high percentage match because I think it's important for me to try to get a few matches this week, if I can.

"I did what I wanted to do and got through the match."

In other matches, seventh seed Argentine Juan Martin Del Potro, the 2009 U.S. Open champion, tamed Russian Nikolay Davydenko 7-5 7-5 while top ranked American John Isner beat Frenchman Richard Gasquet, the eighth seed, 7-6 (6) 6-2.

Canada's Milos Raonic, who moved into the top 10 for the first time this week, continued his good form disposing of Serbia's Janko Tipsarevic 6-4 7-6 (4).