  Large Liquid Argon Time Projection Chambers (LArTPCs) are being increasingly
adopted in neutrino oscillation experiments because of their superb imaging
capabilities through the combination of both tracking and calorimetry in a
fully active volume. Active LArTPC neutrino detectors at or near the Earth's
surface, such as the MicroBooNE experiment, present a unique analysis challenge
because of the large flux of cosmic-ray muons and the slow drift of ionization
electrons. We present a novel Wire-Cell-based high-performance generic
neutrino-detection technique implemented in MicroBooNE. The cosmic-ray
background is reduced by a factor of 1.4$\times10^{5}$ resulting in a 9.7\%
cosmic contamination in the selected neutrino candidate events, for visible
energies greater than 200~MeV, while the neutrino signal efficiency is retained
at 88.4\% for $\nu_{\mu}$ charged-current interactions in the fiducial volume
in the same energy region. This significantly improved performance compared to
existing reconstruction algorithms, marks a major milestone toward reaching the
scientific goals of LArTPC neutrino oscillation experiments operating near the
Earth's surface.
