Chinese athletics superstar Liu Xiang coasted into the semi-finals of the men's 60m hurdles at the World Indoor Athletics Championships here on Saturday. Liu, who was the gold medallist at the 2008 Valencia world indoors to add to previous silver and bronze showings, clocked 7.62sec in finishing his heat a head behind Britain's Andrew Pozzi, who topped the timings with 7.61. But he admitted to being concerned by the starter's orders, with which many athletes had problems on the opening day of action at the Atakoy Arena on Friday amid a raft of false starts. "The starter speaks with a low voice and it was hard for me to understand his 'ready'," said Liu, who set a new Asian record of 7.41sec in Birmingham, England, last month but whose last outing in Stockholm ended with a false start disqualification. "I waited for the athlete on my right to go off to start. I false started in Stockholm and did not want to make the same mistake." The Chinese hurdler is hoping a major technical change to his start will reap dividends not only this weekend but also during the outdoor season to follow. Liu has cut to seven from eight the number of strides he takes before the first hurdle, the "power" phase when hurdlers try to maximise speed from the blocks into the hurdling rhythm that then follows. The alteration has been made, Liu said, in the expectation that it will lead to faster times as he seeks a second Olympic 110m hurdles gold at the London Games this summer. The 28-year-old Liu was a shock gold medallist in the high hurdles at the 2004 Athens Games and remains history's second fastest man in the event. "During the race it felt very relaxed to run," Liu said. "I will get better and better in the semi-final and final on Sunday. I am taking it very serious to run in the final." The men's 60m hurdles has, however, been robbed of a showdown between Liu and Cuban Dayron Robles, reigning Olympics 110m hurdles champion and world record holder, with American David Oliver also missing the cut. Liu's main competition will now likely come from American Aries Merritt, who survived a pair of false starts by world leader Dexter Faulk to win the US trials ahead of two-time world indoor gold medallist Terrence Trammell and American outdoor record holder David Oliver. "It was very easy, nice and relaxed," said Merritt. "It was just the first round, really easy. "I was happy to get through. I feel very confident I can be a medallist if I just execute my race properly." Merritt's team-mate Kevin Craddock did not start his heat, with France's former world junior champion Pascal Martinot-Lagarde also impressing in winning his heat in 7.66sec. "It's my first international championships as a senior," said the 20-year-old Frenchman. "I have to experience sudden stress but this will teach me a lot in my preparation for the future and the Olympic Games in particular."