The McAMS Yamaha rider edged defending champions Shane ‘Shakey’ Byrne by 0.098s, setting the fastest ever lap of the circuit in the morning.
Leon Haslam, who clinched a double victory at the opening round in Donington, was fourth on the times list, just behind JG Speedfit Kawasaki team-mate Luke Mossey.
Qualifying begins on Sunday at 2.30pm with the two races on Easter Monday at 1.30pm and 4.30pm.
Free practice top 10
James Ellison (McAMS Yamaha) 45.120s
Shane Byrne (Be Wiser Ducati) +0.098s
Luke Mossey (JG Speedfit Kawasaki) +0.105s
Leon Haslam (JG Speedfit Kawasaki) +0.118s
Christian Iddon (Tyco BMW) +0.251s
Bradley Ray (Buildbase Suzuki) +0.256s
Dan Linfoot (Honda Racing) +0.343s
Josh Brookes (Anvil Hire TAG Yamaha) +0.344s
Sylvain Guintoli (Bennetts Suzuki) +0.364s
John Hopkins (Moto Rapido Ducati) +0.400s
Read the original article on Eurosport: Ellison tops times in free practice at Brands Hatch Indy