Ryan Newman, a non-playoff driver, was fastest in the first of two Cup practice sessions Saturday morning at Las Vegas Motor Speedway.
Newman posted a top speed of 183.892 mph around the 1.5-mile track.
The Richard Childress Racing driver was followed by Ryan Blaney (playoffs, 183.268 mph), Aric Almirola (playoffs, 183.194), William Byron (183.107) and Daniel Suarez (182.822).
The top 10 was completed by Erik Jones (playoffs, 182.692), Jimmie Johnson (playoffs, 182.513), Regan Smith (182.476), Paul Menard (182.346) and AJ Allmendinger (182.235).
Clint Bowyer (playoffs) had the best 10-lap average at 181.010 mph.
Byron recorded the most laps in the session with 39.
Final practice is scheduled for 3:30-4:20 p.m. ET on NBCSN.