Gabbiadini, whose only previous cap for the Azzurri came in the friendly encounter with England last August, has been called up Cesare Prandelli's squad for the World Cup qualifying double-header against Bulgaria and the Czech Republic and the 21-year-old came to Samp's rescue on Sunday.
The visitors were narrowly edged out by domestic champions Juventus last week but took the lead at the Renato Dall'Ara through Eder, although Davide Moscardelli's header just before half-time and Panagiotis Kone's second-half effort put Bologna, who were hammered 3-0 on the opening weekend of the season by Napoli, on course for all three points.
But Gabbiadini's wonderful 70th-minute free-kick ensured the points were shared.
Bologna started well, with Moscardelli heading over at the far post from a corner, while at the other end Gabbiadini saw his effort fly over the bar from outside the box.
He found the target on his next effort from all of 30 yards, which was saved well by Bologna goalkeeper Gianluca Curci but came straight back into the path of Eder, who put Sampdoria ahead in the 25th minute from the rebound.
Bologna nearly levelled almost instantly, Kone converting after Moscardelli had hit the bar, but the effort was chalked off after Kone was given offside.
The hosts continued to push forward and an outstanding backheeled effort from Rolando Bianchi produced an outstanding save from Sampdoria's Brazilian custodian Junior da Costa.
It proved to be in vain, however, as Bologna did level matters in the 40th minute, with captain Alessandro Diamanti's corner to the near post allowing Moscardelli to steal in and head home.
Gabbiadini was still finding his range after narrowly putting a free-kick over the bar and Bologna nearly took the lead, but this time Moscardelli's header was magnificently kept out by Da Costa.
However, there was nothing the Samp keeper could do to stop a terrific bicycle kick from Kone following Gyorgy Garics' cross from the right as Bologna went in front in the 64th minute.
Their lead lasted just six minutes, though, Gabbiadini firing marvellously into the top corner with a free-kick which left Curci with no chance.
The former Atalanta and Juventus striker nearly landed all three points for his side in the closing stages, but struck inches wide of the left-hand post after being teed up by Gianluca Sansone.