British number one Andy Murray has admitted he struggled at times during his three set win over Tim Smyczek, as he set up a quarter-final meeting with Alejandro Falla (6/1 to beat Murray) at the ATP Farmers Classic.

The Scot was playing his first singles match since he fired his coach Miles Maclagan, and since his Wimbledon semi-final defeat to Rafael Nadal.

While he wasn’t at his best Murray showed few signs of rustiness in his 6-1 4-6 6-2 victory over Smyczek, his only dip in form coming in the second set when his first serve percentage dropped to 42 percent.

Murray was pushed hard at times during the second round clash with Smyczek, who is currently ranked 192 in the world and only won his first ATP Tour match in the first round of the Famers Classic in Los Angeles.

The top seed eventually progressed to the quarter-finals after an evenly balanced third set, breaking in game three as he dumped out the home favourite.

“The first set was good and I started the second set with chances,” Murray told www.atpworldtour.com after the match.

“I was struggling a little bit with my movement, when I got stiff and sore. But I managed to find a way to win.

“There is a huge difference between the grass courts and hard.”

Murray (4/1 US Open winner) will now faces Falla in the quarters after the Colombian knocked out fifth seed Ernests Gulbis 4-6 6-3 7-6 (10-8).