BEIJING – Andy Murray claimed his biggest scalp since career-saving hip surgery with victory over 13th-ranked Matteo Berrettini at the China Open on Tuesday.The 32-year-old defeated the US Open semi-finalist 7-6 (7/2), 7-6 (9/7) in just over two hours in the first round in smoggy Beijing.Murray last week won his first ATP singles match since a major operation in January, as he attempts to get back to a semblance of his best form after a long lay-off.Now ranked 503 in the world, the three-time Grand Slam champion from Britain fought back from a break down to force a tiebreak in the first set against the Italian.Murray showed glimpses of the steely determination which made him number one in 2016 as he grabbed the first set from the eighth-seeded Berrettini.The second set went with serve and again to a tiebreak, with Murray saving two set points on the way to a gutsy win.