If real Mirage can do that, I would be really impressed...
DCS 1.5.6 Open Beta, Mach 1.01 at Sea level (well 350 ft...), 2 Magics and 2800 Kg fuel. MIL Thrust only
Regards
P.S -> Fighters able to supercruise, they do it between 20.000 and 30.000 ft, where air density and hence, drag is low enough. At sea level, there are even few fighters capable to actually go supersonic with AB on.