We report a 2.07-µm Holmium-doped all-fiber laser (HDFL) pumped by a 1.13-µm Ytterbium-doped fiber laser (YDFL). Home-made alumino-germano-silicate holmium-doped fiber (HDF) served here as active medium, optimized in terms of chemical composition and co-dopants’ concentrations. Laser action at 2.07 µm was assessed in simple Fabry–Perot cavity, formed by a couple of home-made fiber Bragg gratings (FBGs), inscribed directly in the HDF; this allowed notable diminishing of intracavity loss of the 2.07-µm laser. HDF was in-core pumped by the 1.13-µm double-clad YDFL with power of ~12.5 W, in turn pumped in-clad by a laser diode (LD) operated at 0.97 µm with ~24.5-W output. Using optimal length (~5.0…5.5 m) of the HDF and employing FBG couplers with reflections of ~99% and ~33%, the HDFL provided ~5.0-W output at 2.07 µm. At these conditions, maximal absolute (slope) efficiencies at 2.07 µm of 39% (42%) and 20% (22%) were measured with respect to 1.13-µm (YDFL) and 0.97-µm (LD) pumps, respectively. Moreover, the record slope efficiency (48%) was obtained for the powers ratio of 2.07-µm output (HDFL) to launched 1.13-µm input (YDFL), which is only slightly less than theoretical quantum efficiency limit (53%) for this kind of pump schemes.