Security personnel men gunned down nine Maoists including a self styled sub zonal commander on Friday, following a fierce encounter at Latehar, around 100 km north west of Ranchi.
The joint team of police and Central Reserve Police Force (CRPF) also recovered a huge cache of firearms and live ammunition.
The three hour long encounter began at around 2am, with the Maoists opening indiscriminate fire from within a house after they were challenged by the forces, about half a km from Luhur village in the area.
The sub zonal commander was Basant Yadav, a dreaded hardcore Maoists of the areas. "This is a major achievement," said Palamu range DIG Lakshman Prasad Singh.
Maoists' activities in Jharkhand have reduced in the past few months following arrest of several top leaders from parts of the state.
But this is the biggest setback for the rebels in the last two years.
Yadav said the raid followed a tip off that turned out to be extremely accurate. No securityman was injured.
The police are trying to ascertain the identity of the six other ultras killed by displaying the dead bodies at the local police station.