The playmaker will be pulling the strings for Bosnia-Herzegovina at next year's World Cup, the country's first, but Rudi Garcia's Roma are the club side fortunate to have the 23-year-old in their ranks.
He whipped home a brilliant free-kick shortly before half-time before driving in a penalty to secure the 2-0 home win over Napoli, who were watched from the stands by their former player Diego Maradona.
Napoli had defender Paolo Cannavaro sent off as he had a bad night, giving way and being punished with cards for each of the dead-ball kicks from which Roma scored.
Gervinho had Roma's first decent opening but lashed a left-footed shot high and wide in the 16th minute, and when Francesco Totti had to be replaced after suffering a muscle injury around the half-hour mark the home side looked to be impeded.
They almost fell behind immediately when former Lazio striker Goran Pandev ran clear behind the Roma defence.
Pandev hesitated slightly over his shot and then sent it too close to Morgan De Sanctis, Roma's former Napoli goalkeeper, who got sufficient on the ball to slow its progress before Daniele De Rossi raced back to slide in and prevent it crossing the line.
Gervinho then saw a penalty appeal dismissed, and may have gone over too easily, before team-mate Kevin Strootman drove a 25-yard shot narrowly over Jose Reina's goal.
Napoli's Lorenzo Insigne missed a glaring chance, placing his low shot from seven yards against the outside of the right post, and deep into first-half stoppage time the breakthrough came at the other end.
Cannavaro brought down Gervinho 22 yards from goal, and Pjanic fired over the wall and into the top right corner, out of Reina's reach.
De Rossi headed narrowly off target early in the second half, before on the hour mark Napoli's Marek Hamsik crashed a shot against the far outside of the post.
The clincher came when Cannavaro dragged back Marco Borriello, resulting in the defender's dismissal and the award of the 71st-minute spot-kick that Pjanic cracked high into the left corner as Reina went low in the other direction.