The Brazilian forward made it three goals in two appearances for his new club following his world record £200.6million arrival from Barcelona - after opening his account in the win at Guingamp last weekend - but it was another debutant who threatened to steal the headlines as Max Gradel gave the visitors a surprise lead.
The hosts dominated early on with Neymar heavily involved in all their good work so it was against the run of play when Toulouse took the lead.
Gradel, on loan from Bournemouth, pulled into space inside the penalty area and met Kelvin Amian's cross perfectly with a superb first-time strike.
Neymar clipped the outside of a post with a header but he would not have to wait much longer for his first home goal. It arrived after 31 minutes with a simple tap-in from close range after Adrien Rabiot's shot was parried by the goalkeeper.
Four minutes later, Neymar set up Rabiot to score with a 25-yard effort to send PSG into the interval in front. It would have been with a two-goal cushion had Alban Lafont not made a fine save to deny Layvin Kurzawa on the stroke of half-time.
PSG pushed for a third goal but it looked like their momentum would be rocked by Marco Verratti's red card - a second yellow for a foul on Christopher Jullien - midway through the second half.
However, the numerical disadvantage did not stop PSG, or Neymar, from being a threat as shortly afterwards he won the penalty which Edinson Cavani emphatically dispatched.
Toulouse refused to go down without a fight, though, and Jullien reduced the deficit after 78 minutes with a header that deflected into the net off Thiago Silva.
PSG were not finished and substitute Javier Pastore quickly restored the two-goal lead with a lovely curling effort from just outside the box.
Kurzawa extended the lead in the 84th minute with a superb volley from a driven cross by Neymar, who put the icing on the cake in stoppage time with a trademark display of quick feet and trickery to beat two defenders and find the bottom corner of the net with a left-foot finish.