Alex Bowman topped the first of two 50-minute practice session Saturday at Chicagoland Speedway.
Making a mock qualifying run, Bowman jumped to the top of the board at 175.942 mph (30.692 seconds). Kurt Busch and Kevin Harvick also made mock qualifying runs to end the session and were second and third fastest respectively. Busch clocked in at 175.873 mph with Harvick at 175.850 mph.
Completing the top five were William Byron at 175.793 mph and Jimmie Johnson at 175.690. Chicago is one of four tracks where Johnson, who has been winless since June of 2017, has never won. Kentucky, Watkins Glen, and the Charlotte road course are the other three.
Ryan Blaney (175.547 mph), Ryan Newman (175.171 mph), Brad Keselowski (174.820 mph), Clint Bowyer (174.616 mph), and Denny Hamlin (174.537 mph) rounded out the top 10.
Defending race winner Kyle Busch was 16th on the chart at 174.160 mph.
Bowman was also quickest in the best 10 consecutive lap category over Harvick, Clint Bowyer, Kurt Busch, and Kyle Larson.
There are 38 teams entered in the Camping World 400. Reed Sorenson is in the No. 27 for Premium Motorsports, Rick Ware Racing has three cars entered with BJ McLeod (No. 51), Bayley Currey (No. 52), and Josh Bilicki (No. 53), and the Spire Motorsports No. 77 is being driven by Quinn Houff this weekend.
No teams need to serve practice holds today.
UP NEXT: Final practice at 2 p.m. ET.