By Wally Pyrah RACING is back at Happy Valley in Hong Kong today with another nine-race programme, following a fortnight’s break to let the new summer grass seeds bed in. Trainer Pierre Ng will have breathed a huge sigh of relief when the wheels of fortune finally turned in his favour, with a winning double at Sha Tin on Sunday putting him narrowly back at the top of the trainers’ title table. Second season trainer Ng finds himself in a prolonged battle with his former mentor Francis Lui, who he leads by one winner, with just 11 meetings of the season remaining. Both trainers are set to make a…