Marek Hamsik rescued a point for Napoli to ensure they stayed top of Champions League Group B after a dramatic 1-1 draw against Besiktas in Istanbul on Tuesday.
A late Vincent Aboubakar goal had given the Turkish side a 3-2 win at the Stadio San Paolo in the reverse fixture two weeks ago.
Nikola Maksimovic was ruled to have handled in the area by referee Mark Clattenburg and Ricardo Quaresma duly converted the resulting spot-kick.
However, Besiktas' lead lasted just four minutes as Hamsik levelled matters in stunning fashion with a sublime long-range curling effort.
Napoli could have broken the deadlock inside the first minute had Manolo Gabbiadini not shot straight at Fabri after meeting Faouzi Ghoulam's dangerous left-wing cross.
But they should have taken the lead just before the half-hour mark as Atiba Hutchinson rattled the outside of the left-hand post with a volley following Kalidou Koulibaly's dreadful attempt at a headed clearance.
Insigne then side-footed over at the end of a well-worked move from Maurizio Sarri's side in what served as a rare moment of quality in the second half.
Napoli were made to pay for their profligacy when Clattenburg decided to point to the spot after Aboubakar's cross stuck Maksimovic on the elbow, with Quaresma dispatching his 78th-minute spot-kick into the bottom-left corner.
Yet Besiktas' joy was short-lived as Hamsik spectacularly sealed a share of the spoils, earning what could be a crucial point with his superb strike from distance.
It could have been even better for Napoli, but Insigne's curling injury-time effort flew narrowly wide.
