Martin Sonka strapped into his Edge 540 V3 race-plane with an acute awareness of just how easy it is to lose at Indianapolis Motor Speedway.

He appeared poised to secure the 2017 Red Bull Air Race World Championship title in the series’ season finale a year ago at IMS. But Japan’s Yoshihide Muroya won the race and, because Sonka finished fourth instead of at least second, the title, too.

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So even though Fort Worth, Texas, is home to the 2018 season finale many expected Sonka to build on Saturday's best qualifying run and clinch the title Sunday. To end the chase at IMS like he couldn’t last October, with a win. But heartbreak awaited the former Czech Republic air force fighter pilot. A.J. Foyt’s pick to win, American Kirby Chambliss, ousted him in the Round of 14 and ensured the championship battle would continue to Texas.

And then another American, Michael Goulian, won the race and snatched the lead from Sonka in the Master Class world championship standings.

“When I found out that I won it was just an indescribable feeling,” Goulian said. “The emotion of one of these days is so high and so low and so high again. My legs almost gave out underneath me there when I found out we won. It’s special for your family and for you and to know that hey, you know what, the three of us today just created a little bit more history on a place that just reeks of history.”

The win is Goulian’s second in 2018 and his first since the season opener in the United Arab Emirates. Goulian trailed Sonka by nine points before the race but now leads the former championship leader by five, 70 to 65. An Australian, Matt Hall, is third with 63 points. Hall missed out on a chance to jump Sonka himself when he failed to make it to the Final 4.

Canadian Pete McLeod finished second Sunday and Frenchman Nicolas Ivanoff rounded out the podium in third. McLeod actually bested Goulian in the Round of 14, but Goulian was the fastest pilot not to win his heat so he still advanced to the Round of 8.

“I was proud of my 1:05.1 time in the Round of 14,” Goulian said. “I said, ‘You know what? I was proud of that flight. We fixed the mistakes and let’s just see what happens.’ And I thought Kirby took the wind out of our sails but then he beat Martin and made our day. And then it just sort of snowballed from there.”

Once that avalanche ended Goulian was on the verge of tears and rolling around on the ground near the airplane hangers inside the IMS oval. Washed over with joy. His win was the first by an American on American soil since Chambliss won in Detroit in 2008, and it came at a track that means a lot to him.

Goulian grew up watching the Indy 500 on TV with his dad every Memorial Day. An open-wheel motor sports fan, he doesn’t need a crash course on the traditions associated with the venue or its famous faces.

“I was actually in a holding pattern in practice looking down on the speedway on Friday, I think Matt Hall was on the track,” Goulian said. “I thought, ‘How did I ever get to this place in my life that I am inside of this speedway doing something that I never dreamed of as a 15-year-old kid when I started flying?’”

Now it’s on to Fort Worth and the chance at his first world title.

Goulian didn’t need this race to show him that the five-point lead he holds over Sonka isn’t much. In his words, it’s nothing. So his team’s plan is to operate as if everyone’s tied.

“Whoever wins that race is most likely going to win the world championship so our goal is to essentially what we did today,” Goulian said. “Try to be really good, don’t try to be perfect. I don’t think there’s any secret in that.”

Another not-so-secret weapon will be the fact he, like McLeod, lives in North America and won't have to worry about jet lag. Goulian believes that's the toughest part of the globe-crossing series.

"Racing at home can be a lot of added pressure and distractions," McLeod said. "But for me this weekend I had a lot of family, fans and support around, which adds a little bit of distraction, but come Sunday I felt good. I had a lot of gas in the tank where a lot of times dealing with the jet lag, the busy schedule, actually it's a challenge."

"Usually my worst day is race day," Goulian added. "It’s not my best day. You’re just so depleted on sleep and food and energy and everything else so you just kind of live from day-to-day and hopefully Sunday’s a good day for you. Here, I woke up feeling as strong as I did on Sunday as I did on Thursday.”

Challenger Cup

Germany’s Florian Berger won his second Challenger Class race of the season and first since the series’ opening race of the season. Kevin Coleman (USA) came in a close second and Patrick Davidson (RSA) rounded out the podium. Baptiste Vignes (FRA) finished fourth. Dario Costa (ITA) came in fifth. Daniel Genevey (HUN) finished sixth.

Kenny Chiang (HKG), who had won the previous two Challenger Class races, didn’t race due to an illness after he qualified fourth Saturday.

Berger is now one race away from a third-straight Challenger Cup series win.

“I’m not calculating any points,” Berger said. “I will go to Fort Worth and do my best and try to win, of course.”

Follow IndyStar sports reporter Jordan Guskey on Twitter at @JordanGuskey or email him at jguskey@gannett.com.