Will Power ended final practice ahead of the IndyCar Grand Prix of Long Beach fastest, heading a Team Penske 1-2-3-4.
Points leader Simon Pagenaud was second, behind Power, but ahead of Helio Castroneves and St. Petersburg race winner Juan Pablo Montoya in fourth.
Mikhail Aleshin ended the session as the highest Honda-powered driver in fifth, with the Russian racer only narrowly avoiding the concrete wall on the exit of Turn 8 during the final seconds of the session.
The session had three minutes added to it at the end, following a late red flag delay after Graham Rahal slammed into the wall at Turn 9.
Graham Rahal finished sixth on the timesheets for Rahal Letterman Lanigan Racing, despite a heavy crash, which will require a substantial repair job if his car is to be ready in time for qualifying.
Josef Newgarden finished seventh, ahead of James Hinchcliffe and multiple Long Beach Grand Prix race winner and four-time Champ Car champion Sebastien Bourdais.
Ganassi's Scott Dixon rounded out the top-10, with the team seemingly unable to replicate their competitiveness from last time in Phoenix on the narrow Long Beach street course.
Andretti's Ryan Hunter-Reay was 14th, despite prompting an early red flag after slapping the tyre barriers at Turn 9.
IndyCar rookies Max Chilton, Conor Daly and Alexander Rossi ended the session 18th, 20th and 21st respectively.