Spencer Pigot was victorious in the first Indy Lights race of the weekend at Laguna Seca and will begin tomorrow's season finale as the championship leader.
The American entered the race six points adrift of Jack Harvey, but leapfrogged the Briton as Harvey ended up just fifth on a difficult day for Schmidt Peterson.
Pigot started his race by getting past teammate Kyle Kaiser for second place as he settled in behind poleman Max Chilton.
However, only a couple of laps into the race, the former Formula 1 driver damaged his tires at the Corkscrew and was forced to pit, handing the lead to Pigot.
Main rival Harvey, on the other hand, fell behind Felix Serralles and Sean Rayhall at the very first turn of the race, dropping down to sixth.
After taking over in first place, Pigot struggled to shake Kaiser, albeit his squadmate never really looked like troubling him for the lead.
At the same time, outside title contender Ed Jones and the fast-starting Rayhall were both able to keep up with the Juncos duo in third and fourth.
And while Kaiser spent almost the entire race around a second behind Pigot, he fell into the clutches of Jones and Rayhall for the final two laps, albeit managed to hold on secure the first Juncos Racing 1-2 of the season.
Jones completed the podium just ahead of Rayhall, who recorded the fastest lap of the race.
Harvey minimized his losses in fifth as he gained one place after a suspension problem forced Serralles into the barriers with three laps to go.
Fellow SPM driver RC Enerson spent the race following Harvey to finish sixth and thus has lost his slim mathematical title chances.
The top ten was completed by Belardi's Juan Piedrahita, Andretti's Shelby Blackstock and Schmidt Peterson duo Scott Anderson and Ethan Ringel, with Chilton recovering to 11th ahead of newcomer Heamin Choi.
Following his fifth victory of the season, Pigot will begin the season finale from second on the grid and with a lead of eight points over Harvey and 21 points over Carlin's Jones, the duo starting fourth and fifth respectively.