Hailie Deegan had one unconquered goal on her ambitious 2018 checklist. On Saturday night in Idaho, she got it. And made history in the process.

Deegan won the K&N Pro Series West race Sept. 29 at Meridian Speedway, becoming the first girl to ever win in the K&N Pro Series. She took the lead from Bill McAnally Racing teammate Cole Rouse on the white-flag lap in the NAPA Auto Parts/Idaho 208.

The 17-year-old NASCAR Next driver tweeted earlier this week her checklist of goals for 2019, with all but the final one checked off. They were, in order: Earn a top-10 finish; qualify in the top five; finish in the top five; qualify in the top three; finish in the top three; lead a race; win a pole; WIN A RACE, with the all caps emphasis Deegan’s own.

PHOTOS: Images from Deegan’s historic victory

“Oh my god,” Deegan said in Victory Lane. “This has to be the best day of my life right here. It doesn’t get any better than this. People don’t understand how many days, how many hours I’ve put into this. How much work I’ve done to get to this moment. It’s just amazing … this is the happiest day of my life. We did it.”

Deegan did it by initiating contact on Rouse, something she had contemplated the night before.

“I was in bed last night thinking, ‘If it comes down, last lap, I’m in second, I’m a car length off of him, what am I going to do?'” Deegan said. “And I found that Turn 1 spot. I knew what exactly I had to do there. I was doing it to some other people just getting right under them to get them a little light to get them, not wrecking loose, nothing crazy, but enough to just get a little under them and make the pass happen. We did that. I knew exactly what I had to do the last lap. I did it, we executed, and we made it happen.”

WATCH: Inside Victory Lane with Deegan and her team

A dejected Rouse after the race said he won’t cut Deegan any slack over the final two races. Rouse finished second to Deegan, with Derek Kraus, Derek Thorn and Ryan Partridge completing the top five.

Deegan’s pole award came in the series’ previous race, at the dirt track in Las Vegas two weeks before her breakthrough at Meridian’s quarter-mile oval. Her previous best finish was second, accomplished twice, including last week.

Through 12 (of 14) K&N Pro Series West races, Deegan has five top-five finishes and 10 top 10s, along with her one win. The series returns to the track Oct. 13 in Roseville, California.