Javier Pastore, Zlatan Ibrahimovic, Mamadou Sakho and Gregory van der Wiel were all on target for PSG at Stade Municipal as Carlo Ancelotti's side capped a memorable 24 hours in style.
A seventh win in eight games for PSG moved it onto 48 points with second-place Lyon away to Ajaccio on Sunday and Marseille, who is on 42, at home to basement side Nancy.
With all the off-field headlines a day after Beckham - England's most capped outfield player - penned a five-month deal with the Parisians, there was little sign of the former Manchester United and Real Madrid star's transfer causing any disruption to PSG's title pursuit.
PSG quickly found its stride on the pitch as Pastore struck with the game's first meaningful chance on four minutes as he volleyed in Ezequiel's Lavezzi's floated cross via a deflection off the unwitting Serge Aurier.
Toulouse goalkeeper Ali Ahamada was equal to subsequent efforts from Pastore and Lucas, while Salvatore Sirigu had to be alert to keep out a shot from Franck Tabanou.
Ibrahimovic then doubled PSG's advantage nine minutes before half-time with his league-leading 20th goal of the season as he connected sweetly with a Lucas cross to plant a powerful header low into the far corner.
Toulouse's task was made all the more challenging as Cheikh M'Bengue was dismissed for a second yellow card just before the break after scything down Lucas.
Ahamada kept the home side in the contest with a pair of excellent saves to deny Ibrahimovic, the second an acrobatic fingertip stop to turn over the Swede's attempted chip, before a desperate sliding block from Aurier thwarted the striker once more.
Ahamada though was powerless to stop an unmarked Sakho netting his first of the campaign on 70 minutes as the central defender steered in a far-post delivery with Lucas again the provider.
Second-half substitute Van der Wiel then added a fourth goal for the visitor two minutes later to cap a fine evening for the leader.