Share on Twitter Juve had won their last three top-flight games by the same 2-0 scoreline but their title prospects took another dent with defeat to a spirited Napoli side at Estadio Diego Armando Maradona. Giorgio Chiellini marked his landmark 400th Serie A appearance by giving away a penalty that was put away by Insigne for what proved to be the only goal of the contest. Cristiano Ronaldo and Alvaro Morata went close to equalising but the visitors, who beat Napoli 2-0 in last month's Supercoppa Italiana, could not find a way through. Napoli were already without a number of key men and lost first-choice goalkeeper David Ospina to injury in the warm-up, meaning a late call-up to the side for Alex Meret.