The 24-year-old had earned his side a draw at Torino prior to the clash at Stadio Luigi Ferraris, and netted his second of the season with a sublime finish in the 80th minute.
Crotone- a candidate for relegation are yet to lose any of their last three league games since their 1-0 home defeat to Fiorentina in March.
Sampdoria dominated proceedings early on, but the visitors– remained relatively untroubled until Patrik Schick put the hosts ahead in the 21st minute.
And Crotone did haul themselves back into proceedings seven minutes after the hour mark, with Diego Falcinelli pouncing in Marcello Trotta’s corner.
However, it was 74th minute substitute Simmy who had the final say six minutes after replacing Trotta.
He expertly converted Diego Falcinelli’s cross from close range leaving goalkeeper Christian Puggioni with no chance.
Though still in relegation zone, Davide Nicola’s men now 24 points from 33 matches and they host AC Milan in their next outing at Ezio Scida.