Arc on horizon for Diamond Necklace after dazzling Goodwood success

Unbeaten filly lands fourth Group One prize Trainer Aidan O’Brien considering Arc trial The high summer sun was still beating down on Glorious Goodwood on Thursday but thoughts were beginning to turn towards the autumn’s showpiece events in France and the US after Diamond Necklace extended her unbeaten record to six races with an effortless success in the Nassau Stakes. Diamond Necklace had just a nose to spare at the end of the Prix de Diane (French Oaks) at Chantilly in June, but her first…