Reigning Formula E champion Nelson Piquet Jr has ended the final Berlin ePrix free practice at the top of the timesheets after unleashing a hot-lap right at the end of an interrupted second session.

Most of the former F1-driver's FP2 running had been compromised by a technical issue, meaning Piquet only completed six-laps during the 30 minute session. But the NEXTEV driver managed to complete a qualifying simulation, while others couldn't, as the stricken Team Aguri machine of Rene Rast disrupted proceedings.

The session had already been red-flagged as Stephane Sarrazin ended his running in the concrete barrier.

Piquet's effort was good enough to deny Bird the top-spot by just 0.013's while Jean-Eric Vergne followed in close company just 0.1's behind his Virgin Racing team mate.

Robin Frijns was fourth for the Andretti Formula E squad ahead of Oliver Turvey and Loic Duval in fifth and sixth.

With FP2 proving to be a much closer affair than the previous session, 0.060's was all that could separate Bruno Senna, Daniel Abt and Mike Conway in seventh, eighth and ninth.

Mahindra Racing's Nick Heidfeld completed the top-ten but was almost 0.5's shy of Conway in ninth.

FP1 pacesetter Sebastien Buemi was 15th fastest while his championship rival Lucas Di Grassi was 11th for Team Abt.