Ramos was making his first appearance for PSG since joining them on a free transfer from Real Madrid this summer.
However, it was Messi who stole the show with three assists as PSG extended their lead at the top of the table to 12 points.
There was a big concern for PSG late on as Neymar had to be stretchered off the pitch with an ankle injury.
Messi took the resulting free kick and set up Marquinhos to equalise with a well-placed header just before the break.
The visitors went ahead with 11 minutes remaining when Messi put Angel Di Maria through on goal and he produced a clinical finish.
Messi grabbed his third assist of the afternoon in stoppage time to set up Marquinhos for another header to seal the three points for Mauricio Pochettino's side.