Alfageme got a consolation goal for Grosseto late on in the 2-1 final score.
The veteran striker was set to leave this summer after injury kept him out for most of the season.
However, Coach Walter Mazzarri insisted he remain and the 37-year-old is proving a hit so far.
Cristiano Lucarelli is in great shape and scored a brace as Napoli beat Serie B side Grosseto 2-1.
“I never had doubts on Lucarelli,” smiled Mazzarri. “If he is in good shape, then he makes his mark in the box and can put a loose ball in the back of the net. I hope he won't get any more injuries, as with time he'll get even sharpe六合投注网站r.
Lucarelli opened the scoring with an acrobatic volley from Christian Maggio's assist, then skipped round Narciso to complete his brace.
“It was a good test, as we were facing an organised team. The tempo still isn't great due to our heavy fitness work, but we are aiming to be at our best for the start of the season and above all the opening Champions League game.”