Schmidt Peterson Motorsports star finished a record 0.0026s behind in the Firestone Indy Lights Freedom 100 race.
Freedom 100 winner retains fourth place in the championship.
The Colombian Carlos Muñoz obtained his third career Firestone Indy Lights victory and teammate Zach Veach finished ninth.
Led from the green flag to the checkered flag.
New recruits Pipo Derani and Dalton Kellett both performed well after overcoming some mechanical gremlins on Friday.
18-Year-Old Zach Veach Collected in Jack Hawksworth's Lap 1 Incident.
Despite recording fastest lap of Barber Race, Veach's finish hampered by cut tire.
Matthew Brabham and father Geoff Brabham now both hold podium finishes on the streets of Long Beach.
Dempsey fought hard to make up positions in the race but could not catch the leaders, and he ultimately brought home a seventh place finish on the tri-oval.
Zach Veach took on his first oval race in Firestone Indy Lights today and brought home a fifth-place finish.
By Eric Mauk: Estaban Guerrieri benefited from a blocking penalty to take the victory in Iowa
Peter Dempsey got his second place finish in an aggressive and thrilling charge for his seventh place starting position.
18-year-old Zach Veach starts from the back in borrowed car from Schmidt Peterson Motorsports
Zach Veach captures his first win in 13 Indy Lights starts.
"The goal has to be to go to Barber Motorsports Park for round two and do the same again,” said Jack Hawksworth.
18-Year-Old Zach Veach records second-best qualifying effort of third, but struggles with a vibration during the Sukup 100 at Iowa Speedway.
18-Year-Old Zach Veach leads his first career Firestone Indy Lights laps and earns his first Podium in the series.