Ghanaian forward Emmanuel Gyasi continued with his rich vein of form in serie B after netting his seventh of the campaign in Spezia's home defeat to Pisa.
The winger scored his side's only goal in the 26th minute after picking up a beautiful pass from Antonini Ragusa to put Spezia in the lead.
But the lead lasted only 12 minutes after Michele Marconi leveled for Pisa before the break.
Pisa added a second deep in the second half through forward Michele Marconi, who scored a brace on the night.
The defeat sees Spezia drop to fourth on the table, but still have a chance of gaining promotion or finishing in a play offs spot.
The 26-year old Palermo born Ghanaian striker has been in outstanding form for the club as they push for promotion to serie A.
His performances has seen him attract interest from several clubs ahead of the summer transfer window, making him the most sought after serie B player.
By Lukman Abdul Mumin