Ricky Stenhouse Jr. edged past Kyle Busch and into the lead, then held on for the final 20 laps for a relatively easy victory.
Perhaps more important, he left Elliott Sadler even farther behind — and took over the Nationwide Series points lead for the first time since the beginning of June.
Stenhouse raced to his fifth Nationwide victory of the year, outlasting Busch on Saturday at Chicagoland Speedway. Once Stenhouse passed Busch on the 180th lap, there wasn't much anyone could do to catch him. Stenhouse, the 2011 series champion, gave up the points lead to Sadler on June 2, but now he finally has it back.
''We knew if we won coming in here to Chicago that we would leave the points leader and that is what it is all about,'' Stenhouse said.
''It is going to be tough as you can see. Elliott was up front as well, and he runs good at every racetrack we have left as well. It is going to be a lot of fun.''
Stenhouse has won two of the last four races — and finished second in the other two. He finished 2.402 seconds ahead of Busch. Austin Dillon was third, followed by Brad Keselowski and Paul Menard.
''I feel like we've got good momentum, but in this business and this sport, anything can change at any time,'' Stenhouse said. ''You've got to keep your guard up. We've got to keep not making mistakes.''
Sadler, who led Stenhouse by a point atop the standings coming into the race, finished eighth. Pole winner Joey Logano was another spot back in ninth.
It's Stenhouse's seventh win in 99 Nationwide starts. Busch, the career victory leader in this series, was trying for his 52nd victory. It would also have been his first win in the series for the team he owns.
Busch and his brother, Kurt, have teamed up this year as co-drivers for Kyle Busch Motorsports on the Nationwide circuit, with Kurt Busch winning at Richmond.
Busch was pleased with his run Saturday, but he couldn't keep up with Stenhouse's No. 6 Ford.
''Our race was really good,'' Busch said. ''The six just come out of nowhere. ... That's the only discouraging part of the day, was just seeing the six drive by us and check out there at the end.''
Stenhouse's win was the first for Roush Fenway Racing at Chicagoland in any of NASCAR's three national series.
''He's certainly on championship form,'' owner Jack Roush said. ''Ricky does a really great job of finding a part of the racetrack that'll work for whatever setup he's given. Throughout the race, he was moving around and finding what the racetrack would give him.''
Stenhouse now leads Sadler by nine points atop the standings. Dillon is another 25 points back.
Dillon was asked afterward about the decision not to help Sadler during the race. The two are teammates with Richard Childress Racing, but Sadler is leaving RCR before next season.
''It's just racing hard for the championship,'' Dillon said. ''RCR is a group working for a championship. We're both wanting to win, and we had to beat the six. We didn't help each other at all today. It hurt us not much - because the six was that much faster. You're just racing hard. I don't know what else to say.''
Stenhouse will drive the No. 17 Ford for Roush next year in the Sprint Cup series. He says he'll compete on that circuit at Dover this year, as well as a couple other races.
''But right now we're really focused on this Nationwide Series championship,'' Stenhouse said. ''If we felt like running a Cup race would distract us, we wouldn't do it, but I just like track time, it doesn't matter in what type of car it is.''