Reddick, in the No. 45 Toyota for 23XI Racing, had topped Group B qualifying in the first round Saturday with a track record lap of 94.210 mph.
However, he wasn’t able to repeat the performance in the final round as Byron topped the speed chart with an average lap speed of 93.882 mph to earn his first pole of the 2023 season.
Reddick ended up second-fastest (93.763 mph) and Austin Cindric was third (93.459 mph).
Sportscar star Jordan Taylor, substituting for the injured Chase Elliott, was fourth and Daniel Suarez rounded out the top-five.
“I don’t know, I was just watching Reddick go out there and set the pace,” Byron said when asked how he gained so much time between the first and second rounds. “He’s been so fast all weekend. Just trying to continue to inch up on him.
“We made big improvements with the car overnight. I thought that practice session (Friday) helped us to get a little bit better and get the back of the car settled down.
“It’s really fun to get the first pole of the year. Obviously, we’ve been on a good stretch here of late. Tomorrow’s what pays. So, we just got to be there at the end.”
Completing the top-10 were Alex Bowman, A.J. Allmendinger, Erik Jones, Kyle Busch and Noah Gragson.
Both Suarez and Bowman had one of their final-round qualifying lap times disallowed for violating track limits.
Round 1 / Group B
Reddick set a track record with an average lap speed of 94.210 mph – the fastest lap of the weekend so far.
Taylor ended up second-fastest (93.696 mph) and Cindric was third (93.556 mph) in the second session.
Also advancing to the final round were Bowman and Busch.
Among those who failed to advance were Bubba Wallace, Joey Logano and Martin Truex Jr.
Former Formula 1 World Champion Kimi Raikkonen was 12th fastest in the Group B session and will start 22nd. Jimmie Johnson, driving a third entry for Legacy Motor Club, was 18th fastest among those in the second group.
At one point in the session, Michael McDowell spun into the tire barrier but was able to continue with the need of a caution.
Harrison Burton’s last time was disallowed for short-cutting the esses during his lap.
Round 1 / Group A
Jones rocketed to the top of the speed chart with an average lap speed of 93.227 mph, which already broke the track qualifying record.
“Man, it felt good,” Jones said. “I hope in the second round we can do it again. Nice to be quick on a road course. It’s not something that has always come easy for me.”
Byron ended up second-fastest (93.179 mph) and Allmendinger was third (93.098 mph).
Also advancing to the final round were Suarez and Gragson.
Among those who failed to advance to the final round were Kyle Larson, Christopher Bell, Denny Hamlin and Kevin Harvick.
Former Formula 1 World Champion Jenson Button ended up 11th fastest in the Group A session, and will start 24th.
Early in the session, Aric Almirola went off course in Turn 1 and briefly went into the gravel but he was able to continue and no caution was needed.
