Andy Murray continued his good form in America by beating Sam Querrey 7-6 (7-3), 6-1 to reach the third round of the Cincinnati Masters.

The British No.1 will have high hopes for the tournament after reaching the semi-finals in Toronto last week, claiming his first win over Novak Djokovic before a creditable performance in defeat to Rafael Nadal.

Murray had been troubled by a long-standing knee injury against Nadal and needed a scan before competing in Cincinnati, however it was his movement that frustrated Querrey as he ran out of ideas and belief.

Murray made the worst possible start to the game as he was broken to love in only the second game.

Murray also began slowly in Toronto last week, losing the second set against Gilles Simon to love in his third-round clash before going on to record that impressive win against Djokovic.

Yesterday, Querrey's big serving and hard hitting was causing the Scot all sorts of trouble early on, but he managed to open his account in the fourth game.

Three games later he got the break back as the erratic side of his opponent's game came out.

Errors were free flowing from both men in a low-quality opening set as Murray levelled matters at 4-4.

The British No.1 won their only previous meeting in Newport, Rhode Island, but that was two years ago when Querrey was still ranked outside the top 200.

The American has made big strides since then, clinching his first ATP Tour title in Las Vegas in March and breaking into the world's top 50. He also reached the quarter-finals in Cincinnati last year, and was still landing enough big blows to take Murray to a tie-break.

However, another wild ground stroke gave the eighth seed an immediate mini-break and he never looked likely to let the advantage slip.

The Scot had the bit between his teeth now, and although Querrey's serves enabled him to save one break point, a sublime lob from Murray earned him a 2-0 lead.

The home hope by now looked out of ideas, with Murray proving equal to everything Querrey could throw at him. A double break was easily achieved as Querrey played into Murray's hands by venturing to the net.

Just when it looked like the match was over however, Murray handed his opponent a lifeline with a poor service game - the break sealed by a double fault.

The next game saw Murray's advantage re-established - another sublime lob helping the Scot break Querrey's resistance - and he easily served out for an ultimately comfortable victory.

Murray put his poor start down to the difference in conditions between Cincinnati and Toronto. "I didn't feel that comfortable on the court," he he said. "It's so fast here compared with last week.

"The balls are flying around and you feel like you can't really swing at the ball as hard as you could last week.

"I've played a lot of matches at night - my last few matches the balls have been dead and here they're flying though the air so quick and I was struggling to control the ball, so I was getting a bit frustrated. But once I calmed down and played a few more games I started to serve better and obviously won comfortably in the second set.

"Against someone like Sam, who is very inconsistent, you need to try to play solidly yourself."

The Scot also shrugged off concerns about his knee and insisted he is in good shape at a key stage of the season - with the Olympics and US Open to come next month.

"It's fine," he continued. "I've known about the knee for five years now, it's something that comes and goes when you play a lot of tennis - some days it's better than others - but it's just a bit of inflammation around the kneecap and that's normal on this surface.

"I've played a lot of matches and physically I feel good," he added. "I'm chasing a lot of balls down, I feel fast on the court and I'm hitting the ball harder."