We report the discovery by the HATSouth survey of HATS-4b, an extrasolar planet transiting a V = 13.46 mag G star. HATS-4b has a period of P approximately 2.5167 days, mass of M sub(p) approximately 1.32 M sub(Jup), radius of R sub(p) approximately 1.02 R sub(Jup), and density of rho sub(p) = 1.55 + or - 0.16 g cm super(-3) approximately 1.24 rho sub(Jup). The host star has a mass of 1.00 M sub(odot), a radius of 0.92 R sub(odot), and a very high metallicity Fe/H = 0.43 + or - 0.08. HATS-4b is among the densest known planets with masses between 1 and 2 M sub(J) and is thus likely to have a significant content of heavy elements of the order of 75 M sub(+ in circle). In this paper we present the data reduction, radial velocity measurements, and stellar classification techniques adopted by the HATSouth survey for the CORALIE spectrograph. We also detail a technique for simultaneously estimating v sin i and macroturbulence using high resolution spectra.