In Warren Joyce's 100th domestic match in charge, the Reds were slick from the outset with a real vibrancy about the performance. Experienced figures like Petrucci, Michael Keane and Jesse Lingard combined well with younger additions to the team.
James Wilson was inches away from a Reece James centre before Conrad Logan made his first real saves to keep out a Lingard snap-shot and a raking drive by Petrucci. The adventurous Saidy Janko carved out the opening for Lingard and another of the Swiss defender's runs led to Wilson being crowded out at the near post.
Lone striker Wilson impressed after Petrucci sparked a breakaway by embarking on a brilliant run but his low left-footed shot flew wide. A goal appeared to be coming and so it proved when Logan needlessly handled outside of his box. Referee Neil Radford did not produce a card but Petrucci meted out his own punishment with a venomous free-kick that dipped between the bar and the keeper to find the net.
Former Reds trialist Jeffrey Schlupp was guilty of blazing over a glorious chance five minutes before the break as the Foxes enjoyed a better spell as the half drew to a close. City continued to improve in the second half and Ben Amos made his first stop when proving equal to a Joe Dodoo effort.
Petrucci was an influential figure in midfield, regularly trying his luck from long range and also feeding Wilson with an inventive through ball that was lobbed off target from a difficult angle by the exciting striker. The same combination saw Wilson's goalbound blast from a Petrucci cross hit Alie Sesay in the face.