DS Virgin's Sam Bird set the fastest time of the first 45-minute practice session of Formula E's Buenos Aires ePix.
The Briton's 1m09.913s time was slower than last year’s first practice session benchmark, which had been set by current points leader Sebastien Buemi on a 1m09.475s.
Bird was the only DS Virgin driver to take part in the session after Jean-Eric Vergne was taken ill overnight and is set to be ruled out of competing at all this weekend.
In the meantime, Daniel Abt placed second in his Abt Schaeffler FE01 with a 1m10.302s, while the NEXTEV duo of Nelson Piquet and Oliver Turvey were third and fourth, underlining improved performance for the team's car.
Buemi sat fifth ahead of title rival Lucas di Grassi, who momentarily stopped on the track before rebooting his Abt Schaeffler FE01 and continuing.
Formula E debutant Mike Conway had an impressive first session and was immediately on the pace, placing 12th with a 1m12.209s lap in his Venturi VM200-FE-01
The session was red-flagged after just seven minutes when Simona de Silvestro crashed her Andretti Spark-Renault, having hit a bump as she exited the pits.
Other incidents saw both Salvador Duran (Team Aguri) and Bruno Senna (Mahindra) run off in to the escape road at Turn 10 and Turn 4 respectively, while Robin Frijns (Andretti) and Piquet had lurid moments at the turn one hairpin.
Frijns later stopped on the track with an apparent software problem.
Yellow flags were briefly also shown for a dog which managed to get through to one of the escape roads. Thankfully, the canine intruder retreated before entering the actual circuit.
|1||Sam Bird||Virgin Racing||1:09.913|
|2||Daniel Abt||Audi Sport Team Abt||1:10.302||+0.389|
|3||Nelson Piquet Jr.||China Racing||1:10.717||+0.804|
|4||Oliver Turvey||China Racing||1:10.752||+0.839|
|6||Lucas di Grassi||Audi Sport Team Abt||1:11.152||+1.239|
|9||Robin Frijns||Andretti Autosport||1:11.429||+1.516|
|10||Antonio Felix da Costa||Team Aguri||1:11.690||+1.777|
|11||Loic Duval||Dragon Racing||1:11.948||+2.035|
|13||Jérôme d'Ambrosio||Dragon Racing||1:12.209||+2.296|
|14||Salvador Duran||Team Aguri||1:12.343||+2.430|
|15||Simona de Silvestro||Andretti Autosport||1:12.432||+2.519|
|16||Bruno Senna||Mahindra Racing||1:12.440||+2.527|
|17||Nick Heidfeld||Mahindra Racing||1:12.578||+2.665|