The hosts were dominant from the off and could have been ahead in the 13th minute when Dani Alves's square pass picked out Neymar, who blasted over the bar from 12 yards out.
It would not be the world's most expensive player to open the scoring in the game, as Bournemouth loanee Max Gradel broke the deadlock for the visitors with a precise low volley 19 minutes in.
Four minutes later the hosts were in the lead, Rabiot playing a one-two with the former Barcelona man before striking a low angled effort past the reach of 18-year-old Lafont.
Midway through the second half, Neymar went to ground in the area under the challenge of Kelvin Amian, but the referee waved play on rather than award a penalty.
On 78 minutes, Jullien thumped a bullet header past Alphonse Areola from a corner to seemingly set up a nervy finale for the hosts, but four minutes later, Javier Pastore collected an Angel di Maria pass and curled a shot into the top left corner of the Toulouse goal.
There was still time for more goals as Neymar's corner on 85 minutes was acrobatically met by Layvin Kurzawa's scissor-volley and rifled into the net, before the Brazilian star capped off an impressive display by weaving into the opposition box and slotting home in injury time.