It is a major challenge to elevate the thermoelectric figure of merit ZT of materials throughenhancing their power factor (PF) and reducing the thermal conductivity at the same time.Experience has shown that engineering of the electronic density of states (eDOS) and the energyfiltering mechanism (EFM) are two different effective approaches to improve the PF. However, thesuccessful combination of these two methods is elusive. Here we show that the PF of β-Zn4Sb3can greatly benefit from both effects. Simultaneous resonant distortion in eDOS via Pb-dopingand energy filtering via introduction of interface potentials result in a ~40% increase of PF and anapproximately twofold reduction of the lattice thermal conductivity due to interface scattering.Accordingly, the ZT of β-Pb0.02Zn3.98Sb3 with 3 vol.% of Cu3SbSe4 nanoinclusions reaches a valueof 1.4 at 648 K. The combination of eDOS engineering and EFM would potentially facilitate thedevelopment of high-performance thermoelectric materials