Jean-Eric Vergne led a DS Techeetah 1-2 in the opening practice session for the Bern E-Prix, with four of the championship contenders in the top four.
The opening practice session of the day got underway in overcast conditions with the field heading straight out onto the Swiss circuit in order to make the most of the available running.
The Audi Sport ABT Schaeffler duo of Lucas di Grassi and Daniel Abt were the first to set lap times around the 2.750km circuit, with the rest of the field soon following suit as Pascal Wehrlein set the early pace.
The times started to tumble as drivers became more acclimatised to the circuit, with Oliver Rowland and Robin Frijns bringing the benchmark down to the 1:23s mark.
A constant change of pace setter characterised the sessions, with Mitch Evans, Andre Lotterer, Maximilian Günther and local hero Sebastien Buemi all taking turns in P1.
After the first long runs Wehrlein made the most of a clear track to go fastest, but was soon beaten by Rowland and Stoffel Vandoorne, the latter becoming the first driver to go under the 1:22s mark.
With drivers finding the limits and utilising attack mode, the benchmark fell further and further with Sam Bird, di Grassi, Edoardo Mortara and Wehrlein all taking P1 within seconds of each other.
Vergne then made the most of a clear track to pump in a 1:19.281s, 1,127s clear of Wehrlein’s prior time. The Frenchman was soon joined at the top of the times by teammate Andre Lotterer, while di Grassi, Günther and Mortara moved up into the top five.
A final surge of activity saw the times continue to change further, but no one could usurp Vergne of the top time and he led a DS Techeetah 1-2 with Lotterer lapping 0.111s behind his teammate.
Championship contenders di Grassi and Frijns finished third and fourth respectively, while Evans put his Panasonic Jaguar Racing into the top five.
Abt ended the session sixth ahead of compatriot Günther, while Mortara, d’Ambrosio and the NIO of Tom Dillmann rounded out the top ten.