Musa, 25, made a big summer move to the Foxes after four successful seasons at Russian side CSKA Moscow, and is already looking like good value for money, following his impressive display against the Catalans.
A double from teenager Munir El Haddadi either side of a solo effort from Luis Suarez had put Luis Enrique’s side three goals up in a very one-sided first half that saw stand-in captain Lionel Messi run the show with ease.
However, Foxes manager Claudio Ranieri introduced the Nigerian forward for Demarai Gray in a raft of substitutions at half-time and it was a different game altogether as Musa ran the Barca defence ragged with his pace and tenacity.
The former Super Eagles captain star struck twice in 18 minutes to throw his side a lifeline, however, they took their foot off the gas and Barca substitute Rafa Mujica sealed victory with a close range finish in the 84th minute.
Musa is expected to be in action when the English champions take on FA Cup holders Manchester United in the Community Shield on Sunday.