A power generation plant has two internal combustion engines (ICE) coupled in a compound configuration to operate electrical generators. A first ICE is a piston/cylinder engine producing high temperature and high pressure exhaust. The exhaust is coupled to the combustion air inlet of the second ICE, which is a gas turbine engine. A heat exchanger transfers heat from the exhaust of the first ICE to a bottoming cycle for additional power generation, also reducing the temperature at the turbine engine combustor. The second ICE (the gas turbine) is operated without an intake compressor, relying instead on the high pressure of the first ICE exhaust. The drive shaft of the gas turbine (or an associated generator/motor or a common shaft) operates a multi-stage turbo-compressor at the combustion air intake of the first ICE for improving engine power output without sapping exhaust energy as with a turbocharger.