Logano, the lone Sprint Cup regular in the race, earned his second Nationwide win of the year and No. 20 for his career. He also won at Dover in June.
Hornish held on for second, giving car owner Roger Penske the top two spots. Austin Dillon finished third, earning a $100,000 bonus.
Elliott Sadler had the lead on a restart with 24 laps remaining. But the defending race winner faded as Hornish moved in front on the track where he won an IndyCar race in 2002.
Hornish looked in position to secure the victory when Logano roared into the lead and went on to the victory while the rest of the Sprint Cup drivers took the weekend off.
Sadler finished fourth, and was followed by Brian Vickers, Parker Kligerman and Trevor Bayne. Illinois native Justin Allgaier, Brad Sweet and Matt Crafton rounded out the top 10 in the first Nationwide stop of the year at Chicagoland.
The series returns in September on the same weekend that the Chase for the Sprint Cup championship begins at the track.
Sadler and Regan Smith did not see very much of each other one week after their collision at New Hampshire led to a midweek phone call to clear the air. Sadler confronted Smith right after the race, promising he would not win the series title, and then said he would race the No. 7 Chevrolet differently in the future.
There were no such problems at Chicagoland, with Sadler racing near the front and Smith struggling with the feel of his car all day long. Smith, who entered the race with a five-point lead over Hornish in the series standings, slid into the infield on Lap 129, resulting in caution No. 4. Smith finished 13th.
Hornish won his second career pole earlier in the day, and then led the first 49 laps. But he was flagged for speeding into pit road and sent to the back of the field for a restart on lap 54. He quickly climbed back into contention, but was unable to run down Logano at the end.
Sadler was still upset with Smith when the series arrived in Chicagoland this week. The dispute started when Smith spun Sadler around on the final restart in last Saturday’s race at Loudon, costing him a shot at a solid top-10 finish and a potential $100,000 bonus.
Smith took responsibility for the accident, and Dale Earnhardt Jr., the co-owner of Smith’s car, also reached out to his longtime friend Sadler. But it did little to assuage Sadler’s anger.
“We’re here to win the championship, period,” Sadler said after Saturday’s practice sessions, “and I honestly think as good as we’ve been running the last month or so, I don’t think he’s going to run good enough to run with us anyway.”
He backed up his words on the 1.5-mile, D-shaped oval right outside of Chicago. But the Penske cars proved to be too much in the end.