With the win seemingly in the bag, a late caution flag forced Farr to defend his lead on a full restart. But his experience was too much for McFadden as he held on to win.
"I could see James was running pretty decent in behind us there so I had to cheat myself a little bit on that last restart by going in low [on the race track] even though I knew it was faster up on the top," said Farr, a former Australian sprint car champion.
"I just couldn't allow him to have the space underneath me to make a slide-job pass or that could've been it."
The Americans faced a tough night as Kraig Kinser had a podium position pulled out from under him on the last lap, while Jonathan Allard suffered a huge crash earlier in the race.
In the midget class, Brad Mosen came out on top of an epic two-man battle with fellow Aucklander Hayden Williams to win the feature race. Both drivers started on the front row and escaped the field early on but as each driver tried to defend the lead, the other would attack with vigour, trading passes almost every lap.
"It's never easy with Hayden, we went toe-to-toe that whole race and I knew we were faster and I really wanted to show him that we're here to play and what better night to do it than tonight; we were both on the front row and it's man on man," said 27-year-old Mosen.
"This time it was our cigar and that's just as good as it gets."
The Baker family from Auckland are still undefeated in the TQ class this summer after Scott Baker held on to win ahead of Napier's Duane Todd; Scott's brother Ryan finished third.
Meanwhile, Neville McNabb scored an F2 midget hat-trick, winning his third feature event in a row.
The action at WxC Speedway - Western Springs returns this Saturday night for round two of the Porter Hire International Sprint Car Series.
For more information, visit www.springsspeedway.com.
