A Piece Of Heaven’s 7-1 success in the Chester Cup, the most popular and historic race of the year at the world’s oldest racecourse, was a fine way to round off the track’s May festival meeting on Friday, not least after a day when, for around an hour or so in early afternoon, the event had teetered on the edge of an expensive, embarrassing disaster. The odds that the middle day of Chester’s showpiece event would be abandoned, with around 15,000 spectators at the track for Ladies’ Day, seemed to be shortening at 2.30pm on Thursday, as a delegation of jockeys and trainers inspected the turf on the home turn. Several riders had reported slipping in the opening race, prompting emergency remedial work by Chester’s ground staff. A few minutes earlier, Maureen Haggas, assistant to her husband, William, at one of Newmarket’s biggest stables, had scratched Morshdi, the second-favourite, from the Dee Stakes, the day’s big Derby trial.…