Lleyton Hewitt and Marinko Matosevic have suffered second-round defeats at the Cincinnati Masters on Wednesday.

Matosevic lost 6-3 7-6 (7-1) to big-serving American John Isner, while Hewitt capped a bad day for Australia with a 6-1 6-4 defeat at the hands of Italy’s Fabio Fognini.

Andy Murray began his final preparation tournament for the US Open, which starts on August 25 at Flushing Meadows, with a smooth 6-3 6-3 victory over Portugal’s Joao Sousa.

The eighth-seeded Murray, who lifted the Cincinnati trophy in 2008 and 2011, is searching for his first title since winning Wimbledon 13 months ago.

Since returning in January from back surgery, Murray has enjoyed only modest results, with his best 2014 showings semi-finals at Roland Garros and Acapulco.

Both of the Scot’s Cincinnati titles came in finals against Novak Djokovic, the top seed who has won every Masters 1000 title save this one.

“I got the win and that’s the most important thing,” Murray said

“It’s very different conditions here this week.

“A lot of guys struggle to control the ball, I was happy to come through.”

Taiwan’s Lu Yen-Hsun stunned Czech fourth seed Tomas Berdych 3-6 6-3, 6-4 while Poland’s Jerzy Janowicz upset world No.8 Grigor Dimitrov 6-4 3-6 6-3 four days after the Bulgarian played a semi-final in Toronto.