Fabio Leimer continued his streak and took his fourth consecutive Saturday race victory of the International Formula Master season.
The 20-year-old broke away at the start of the race but was reeled in by title rival Josef Kral in the closing stages and had to withstand intense pressure in the closing laps to hold on at the front.
Kral closed the gap from over four seconds to be right under Leimer's wing on the final lap. He had taken a look around the outside of Leimer at Hawthorn two laps previously, but there was no chance to pass on the final lap.
"I thought maybe I would not win the race because at the end he was much faster than me," said Leimer. "It was really close, but in the end it wasn't possible for him to overtake me, so I am really happy."
Leimer then inched away as Kral understeered at Westfield while trying to hang on in the slipstream and the pair crossed the line less than half a second apart.
Sergei Afanasiev was a quiet third, with Pal Varhaug, Erik Janis and Patrick Reiterer completing the top six in formation.
The other battle going on in the race was for seventh place, where Alexander Rossi held off Alessandro Kouzkin and Vladimir Arabadzhiev.
Kouzkin and Rossi will share the front row for tomorrow's reverse grid race.
Results to follow