Mitch Evans fastest with a 1:30.361 in the first practice of a packed Monaco ePrix schedule.
Formula E returned to the previous schedule of having all the track running on the same day after favouring the FP1 session to happen the day before.
Andre Lotterer’s early issue with his breaks forced all four Porsche-powered cars to spend extended time in the pits during the session.
Towards the end of the session, Porsche confirmed that an issue with the regeneration software caused the problems.
The DS Penske’s of Stoffel Vandoorne and Jean-Eric Vergne showed pace throughout the session, being at the sharp end of the times for most of the running.
Vandoorne finished the session second, .126 seconds adrift of Evans’ time, while teammate Vergne was fifth fastest.
Fellow Stelantis company Maserati had a strong session off the back of their first podium in Berlin, with their cars ending the session third and fourth.
After a difficult time in Berlin, McLaren was back in the top ten times, with Rene Rast ending the session in sixth.
Despite his earlier issues, Lotterer set a time worthy of the top ten. He finished the session in ninth, just over seven-tenths adrift of the fastest time.
Sam Bird rounded out the top ten times for Jaguar as the British team continues to try and string together a positive run of results.
Lucas DiGrassi locked his rears into Saint Devote towards the end of the session, bringing out a yellow flag while many drivers set their flying laps.
The Brazillian driver managed to nurse his Mahindra back to the pits for a front wing change.
Porsche still has some lap time left to find, with their drivers ending the session in 12th and 13th while the sister car of Jake Dennis came home in 15th.
Track action gets back underway at 8 am local time for FP2.