Lucas di Grassi seized the points lead back after a solid win at the Long Beach round.
The Abt driver beat Venturi's Stephane Sarrazin with team-mate Daniel Abt claiming the final podium spot.
Sebastien Buemi had a scrappy race, ultimately finishing three laps down in 16th position.
Simona de Silvestro became the first female driver to score points in the all-electric series by finishing ninth for Andretti, while IndyCar part-timer Mike Conway claimed his maiden FE points in 10th.