A incident-strewn feature race, which came after an abandoned sprint race on Saturday, saw four of the top six in the standings crash out, while the remaining two were handed 10-second penalties for collisions.
The mixed-up order saw Trident driver Novalak, who had scored just two points in 2023 before this weekend, take his first win since his title-winning BRDC F3 campaign in 2019.
Lining up 13th, Novalak was inside the top 10 by the first safety car, which came moments into the opening lap as Jack Doohan spun into retirement on the run to the banked Turn 14, while up ahead Frederik Vesti also rotated but kept his Prema-run car going.
Racing resumed on lap four, with pitstops commencing a few laps later as poleman Jak Crawford retained the lead for Hitech.
Championship leader Theo Pourchaire was next to crash out, heading straight into the Turn 7 barriers on his post-stop outlap.
Novalak and both Prema cars headed into the pits before the safety car was deployed but Vesti soon encountered trouble as both his rear tyres parted company with his car, putting the Dane out too.
The safety car period ended on lap 16 as Prema's Ollie Bearman and Victor Martins (ART) clashed, with with Briton retiring and his adversary handed a 10-second penalty.
But Novalak held firm and took his maiden win, with Zane Maloney in second for Rodin Carlin ahead of Crawford.
The only driver in the top five in the standings to score was Martins, demoted to ninth by his penalty as Iwasa, who also received a penalty, finished 13th.
The formation lap got underway behind the safety car, with a rolling start as half the track remained wet from overnight rainfall, though most of the field opted for slick tyres.
Doohan's car lost traction and swapped ends before becoming stranded at the bottom of the banking as the pack was released, then Crawford locked up at Turn 1 but held the lead.
Bearman had been forced to slow to avoid Doohan, and was then hit from behind at Turn 1 by Juan Manuel Correa (VAR), who earned a 10-second penalty for the indiscretion. It was of little consequence to Bearman, who dropped to 14th, while Martins too ran into the gravel and fell behind him.
The chaos benefitted Pourchaire, who was up to sixth by the end of the first lap.
Racing resumed on lap four as Ayumu Iwasa (DAMS) made contact with Campos driver Kush Maini, cutting across his front wing at Turn 1 and running across the gravel. Maini was forced to pit as Iwasa was handed a 10-second penalty.
By lap six, Bearman had made it back up to ninth, before the pitstops started with Maloney, who peeled in from third.
Pourchaire had closed on Hadjar for fourth two laps later as Crawford and Dennis Hauger (MP Motorsport) pitted from first and second.
Hadjar and Pourchaire then stopped, with the latter emerging ahead, before his Turn 7 shunt. Along with Novalak, the Prema pair dived into the pits in anticipation of another safety car in an ambitious double stack.
But the gamble failed to pay off for Vesti, who lost both rear tyres moments later before the safety car was deployed.
The chaos handed Novalak the lead, with Crawford and Maloney second and third ahead of home favourite Richard Verschoor (VAR) and Martins.
Maloney passed Crawford for second around the outside of Turn 1 on the restart, with Bearman making it past Martins in the same place for fifth.
But the Ferrari Driver Academy member's race was ended moments later after contact with the reigning F3 champion, who failed to leave Bearman enough room at the exit of Turn 3 and forced him into the wall.
Martins, who was running fifth, was dropped to ninth by the resulting penalty.
Out front, Novalak had pulled a 2.4s gap to Maloney, who was unable to close the gap to the leader although he held off a charging Crawford.
Verschoor finished fourth, with Hauger and Hadjar in fifth and sixth. Enzo Fittipaldi was seventh for Rodin Carlin, with Amaury Cordeel (Virtuosi), Martins and Correa rounding off the top 10.
