The Argentinian’s opening goal could have been ruled out for offside while he earned the Azzurri all three points from the penalty spot after an infringement which was hard to spot.
Iago Falque had brought Genoa level, while Napoli missed their easiest chances to ensure the controversies would not matter with Jonathan De Guzman guilty of the biggest misses.
Rafael Benitez’s men nevertheless celebrated three important points, which took them back above both Sampdoria and Lazio into third, where they are just six points behind second-placed Roma.
Also on Monday evening, Udinese picked up their first win in six attempts to climb above the two Milanese teams into eighth place in the standings, despite ending their 2-1 win over Empoli with 10 men.
Antonio Di Natale put Andrea Stramaccioni’s side in front after 19 minutes, but Riccardo Saponara levelled from the spot with his first goal of the season for Empoli.
Silvan Widmer earned Udinese the points with what appeared to be a cross before Panagiotis Kone was given his marching orders, but the guests held on to all three points.