Buemi fastest in Monaco practice sessions
Sebastien Buemi edged out Sam Bird to top both practice sessions as Formula E returned to Monaco.
The Renault e.dams driver led the way in FP1 with a 52.795s, and then improved marginally on that effort with a 52.729s in FP2.
That was a full second faster than the practice benchmark when Formula E first visited the principality in its inaugural 2014/15 season.
Buemi and team-mate Nico Prost were the only leading drivers to complete a qualifying simulation in first practice.
When Bird turned his DS Virgin Racing car up to 200kW in FP2, he went quickest with a time 0.002s slower than Buemi's FP1 best.
That looked like it would let Bird top the second session, but Buemi improved with a late flying lap to vault to top spot by 0.068s.
Less than three tenths of a second covered di Grassi in fourth and Prost, who hit the wall with his front-right wheel through the Antony Noghes corner, in ninth.
Jose Maria Lopez (cleared to continue participating after recovery from an injury), Loic Duval, Daniel Abt and Nelson Piquet Jr filled the positions between those two, with Stephane Sarrazin completing the top 10 for Venturi.
'SILLY' TURVEY/ROSENQVIST CRASH ENDS FP1 EARLY
The opening session was ended slightly early by a bizarre accident involving Oliver Turvey and Felix Rosenqvist.
Rosenqvist rear-ended Turvey heading into the Turn 3 hairpin, which reconnects the Formula E track with the Formula 1 layout via the exit of the chicane.
With double yellow flags being waved for the barely-moving Buemi on the inside, Turvey then braked heavily to avoid passing the Renault under the caution.
Rosenqvist was not expecting this, and ploughed into the back of the NextEV car.
"You have to be prepared to stop," Turvey said. "I didn't even see him [Rosenqvist]. It was a silly accident."
Roseqnvist explained: "I braked earlier than on my lap before.
"I expected Oliver to pass Buemi but he was afraid to get a penalty and panic braked.
"It was a misunderstanding, this is the problem when people are slowing down."
Both took part in FP2 and finished next to each other on the timing screens, with Rosenqvist 16th and Turvey 17th.