Inevitably all eyes were on the Brazil star, whose first contribution was to loft an ambitious pass from deep towards the run of Di Maria which proved just too heavy.
And the world's most expensive player had also been involved in the build-up to the opener in the 52nd minute, a Jordan Ikoko own-goal, as he attempted to play in Cavani. I am very calm.
He however started their second Ligue 1 fixture, alongside fellow South Americans Edinson Cavani and Angel Di Maria up front.
Guingamp, a sleepy little town 500 kilometres west of Paris with a population of barely 7,000, may have been a slightly incongruous setting for such an occasion but the match was broadcast live in more than 180 countries according to his new club.
Emery's side are also desperate to regain the French crown after losing out to Monaco last season.
All in all, it was a pretty ideal debut for Neymar and he's already gone a tiny way to repaying the ridiculous fee paid for him; no doubt these will have been the first major contributions of what is sure to be an extremely colourful period of his career.
Neymar, playing mainly as an inside left, threatened sporadically in the opening stages before his cross in the 35th minute found compatriot Marquinhos, who headed against the woodwork.
Neymar continued to treat the crowd to some delicate turns, but it was a rookie mistake that put the visitors ahead seven minutes into the second half, when Ikoko's pass back to his keeper ended up in the net. The assist was for Edison Cavani's 62nd minute goal. They are one of five teams to have maximum points after two games.
Despite Monaco fans' concerns that French prodigy Kylian Mbappé might be leaving, they know they can still trust Radamel Falcao after the Colombian striker hit a hat-trick.
France worldwide Mbappe was left on the bench amid speculation that he wants to join PSG but he was not needed as Monaco equalled the record of 14 consecutive wins in the French league.