Alex Bowman had a consistently fast Hendrick Motorsports Chevrolet in opening NASCAR Cup Series practice at Auto Club Speedway in Fontana.
Bowman put down the fastest lap early in the 50-minute session and then again during a late run. At 179.439 mph (40.125 seconds), Bowman was significantly faster than Kyle Larson. Larson clocked in at 177.703 mph.
Rookie Tyler Reddick was third quickest at 177.607 mph. Kurt Busch was fourth fastest at 177.375 mph while Matt DiBenedetto rounded out the top five at 176.609 mph.
Jimmie Johnson was sixth fastest at 176.510 mph with Martin Truex Jr. seventh fastest also at 176.510 mph. At eighth on the speed chart was Ricky Stenhouse Jr. at 176.449 mph as Ryan Blaney was ninth at 176.117 mph and Brad Keselowski wound up 10th at 176.035 mph.
Ross Chastain was 14th fastest in his week-to-week role driving the No. 6 Ford for Roush Fenway Racing.
Defending race winner Kyle Busch was 24th fastest at 174.355 mph.
There were no incidents in opening practice.
Bowman was also fastest in the best 10 consecutive lap average over Kurt Busch, Cole Custer, Truex, Kevin Harvick, Denny Hamlin, and Chase Elliott.
UP NEXT: Final practice at 5:35 p.m. ET.