Hybrid nanolaminates (NLs) consisting of alternating layers of metal and metal oxide exhibit excellent mechanical properties and resistance to irradiation damage which is critical for various structural and functional applications. The strength and ductility of NLs are a strong function of the layer thickness and the interfacial characteristics. Critical investigations of the mechanical behavior by in situ nanomechanical testing in a transmission electron microscope (TEM) and the corresponding microstructural evolution within individual layers as well as at the interfaces become important. In situ studies not only allow us to elucidate the underlying deformation mechanisms but also the influence of electron beam irradiation (EBI) on these mechanisms. In our study, we present Al/a-Al2O3 NL model systems invloving amorphous/crystal interfaces that exhibit enhanced ductility over 50% with a high ultimate tensile strength above 1550 MPa under uniaxial tension. The extreme plasticity obtained here results from the time-dependent viscoplastic response under low-strain rate (10-6 s-1) which is induced by EBI. The influence of EBI on the stress-strain behavior was systematically confirmed by switching on and off the electron beam which led to drastical changes of the mechanical response. The microstructure of the NL defomed under beam-on was characterized by significant delocalization of the plasticity. Intriguingly, Al-layers exhibit localized necking at the majority of grain boundaries (GBs). This suggests GB diffusion creep is the dominant mechanism operating at low-strain rates and this feature did not manifest itself in samples deformed at higher strain rates or in the absence of EBI. Furthermore, the localized plasticity at GBs is associated with GB migration which we have analyzed in our study based on the novel combination of nanoscale digital image correlation (DIC) with nanomechanical testing inside TEM. The role of the crystal/amorphous interface and the the transmission of plastsicty at this interface is also discussed.