Scott Dixon won a wild IndyCar race at Sonoma after championship leader Will Power had led the early stages. Power later spun during a safety car but recovered to 10th, putting him 51 points clear of team-mate Helio Castroneves ahead of next weekend’s season finale.
In the supporting Indy Lights, the title was decided on a tie-break after two wins for Jack Harvey. That wasn’t quite enough for the British rookie, who lost out to the more consistent Gabby Chaves after the pair tied on points.
READ MORE: Chaves earns Indy Lights title on tiebreaker
Raffaele Marciello won the Feature Race after a fantastic duel with local hero Stoffel Vandoorne, both men proving that rookies can impress in GP2. Johnny Cecotto was third after briefly leading early on.
Nasr won the Sprint Race after a blistering getaway from fifth on the grid. Cecotto pushed him hard but the Brazilian always seemed to have an answer. Palmer was third and now leads Nasr by a reduced 32 points with three race weekend remaining.
A frantic and sometimes strange GP3 Feature Race was won by Dean Stoneman, who led a British sweep of the top four ahead of Dino Zamparelli, Nick Yelloly, and Jann Mardenborough. The contest should have been won by Matheo Tuscher, but the 17-year-old Swiss spun out of a comfortable lead with only a few laps to run.
Championship leader Alex Lynn and title rival Richie Stanaway were seventh and eighth after making the wrong tyre call, but that put them one-two for Sunday's reverse-grid Sprint Race. They delivered, taking a one-two in Lynn's favour after an intense mid-race scrap.
Completing the Belgian Grand Prix support action, Earl Bamber took the Porsche Supercup championship lead with victory at Spa. He leads Kuba Giermaziak by a slender three points with three races to run.
READ MORE: Bamber flies to Spa victory
Joao Pablo de Oliveira took the lead in Japan’s Super Formula championship with victory from pole at Motegi. Hiroaki Ishiura was second with Andrea Caldarelli, who stood in for F1 debutant Andre Lotterer, taking third. Despite missing the race Lotterer remains firmly in the title hunt, sitting just 6.5 points behind De Oliveira with four races to run.
READ MORE: Race highlights video
Penske driver Joey Logano took his third NASCAR Sprint Cup win of the year on Saturday night, beating team-mate Brad Keselowski and Matt Kenseth at Bristol Motor Speedway. Just two races remains before the Chase portion of the season begins. The supporting Nationwide Series race was won by Truck Series regular Ryan Blaney, who beat Kyle Busch and points leader Chase Elliott to Victory Lane.