De Silvestro took the lead from polesitter Jonathan Bomarito on Lap 24 of what would be a 38-lap race when gearbox issues forced Bomarito into an off-course excursion in Turn 1 at the end of the Shoreline Drive straightaway.
De Silvestro joins Katherine Legge as the only women to win races in Atlantic Championship competition. Legge owns a total of three Atlantic victories, the last of which came at San Jose on July 31, 2005. Legge also picked up her first career Atlantic win at Long Beach in 2005.
Alan Sciuto won second-place just in front of Canadian Kevin Lacroix of Walker Racing. It was Lacroix's first podium result since he won in his second career Atlantic start in the second race of a doubleheader at Portland last June. Lacroix is beginning his first full season of Atlantic competition.
Newcomer Jonathan Summerton came in fourth followed by polesitter Jonathan Bomarito.
Toronto's James Hinchcliffe crossed the line in 10th place, his race set-up being far from perfect.