  V923 Sco is a bright ($V$ = 5.91), nearby ($\pi$ = 15.46$\pm$0.40 mas)
southern eclipsing binary. Because both components are slow rotators, the
minimum masses of the components are known with 0.2% precision from
spectroscopy. The system seems ideal for very precise mass, radius, and
luminosity determinations and, owing to its proximity and long orbital period
($\sim$ 34.8 days), promises to be resolved with long-baseline interferometry.
  The principal aim is very accurate determinations of absolute stellar
parameters for both components of the eclipsing binary and a model-independent
determination of the distance.}
  New high-precision photometry of both eclipses of V923 Sco with the MOST
satellite was obtained. The system was spatially resolved with the VLTI AMBER,
PIONIER, and GRAVITY instruments at nine epochs. Combining the projected size
of the spectroscopic orbit (in km) and visual orbit (in mas) the distance to
the system is derived. Simultaneous analysis of photometric, spectroscopic, and
interferometric data was performed to obtain a robust determination of the
absolute parameters.
  Very precise absolute parameters of the components were derived in spite of
the parameter correlations. The primary component is found to be overluminous
for its mass. Combining spectroscopic and interferometric observations enabled
us to determine the distance to V923 Sco with better than 0.2% precision, which
provides a stringent test of Gaia parallaxes.
  It is shown that combining spectroscopic and interferometric observations of
nearby eclipsing binaries can lead to extremely accurate parallaxes and stellar
parameters.
