The performance of electrocatalysts is closely related to their supporting materials since their properties such as heteroatom doping, porosity, graphiticity, and electrical conductivity play a decisive role on catalyst performance. We report here the preparation of N-doped highly graphitized porous network-structured carbon (N-HGC) as a catalyst support for Ru nanoparticles (NPs) catalytically active for hydrogen evolution reaction (HER) using pyrolysis of g-C₃N₄. The as-prepared N-HGC shows high graphiticity confirmed by XRD and Raman analyses, high electrical conductivity, and large surface area along with large amount of open mesopores, containing the proper amount of N doping rich with high pyrrolic-N content for homogeneous distribution of Ru NPs. This Ru/N-HGC catalyst shows a remarkably low overpotential of 9.6 mV (vs RHE) at 10 mA/cm², which is near ideal and far better than state-of-the-art Pt/C. It also illustrates superb stability, maintaining the HER activity for 200 h and 10k CV cycles without any significant degradation. This superb HER performance is attributed to the robust N-HGC support featuring thin carbon structure, high electrical conductivity, suitable porosity, and N pyrrolic doping. The atomistic basis for the low overpotential is explained via Grand Canonical Quantum Mechanics (GC-QM) calculations. These calculations show that the pyrrolic-N in the support strengthens the coupling to Ru NP and weakens the binding of H to Ru NP, improving the rate determining Tafel reaction.