The 37-year-old Englishman started the game on the substitutes’ bench but came on to replace Javier Pastore in the 76th minute at Parc des Princes.
He then played a part in setting up PSG’s second goal in stoppage-time, linking up well with Jeremy Menez before Zlatan Ibrahmovic turned the ball home from close-range.
“It was a special night for the team and for me,” Beckham told reporters after the match.
“I received a great welcome. To wear the jersey of PSG and get on to the pitch, it was all very special.
“To win against Marseille and increase our lead on them to eight points, this was a very important victory for us.”
PSG, which saw its victory restore a three-point lead over Lyon at the top of Ligue 1, faces rival Marseille again on Wednesday night, this time in Coupe De France action.