Jimmie Johnson is the leader of the Kobalt 400 at Las Vegas Motor Speedway at the halfway point in the 267-lap race.
Johnson, a four-time winner at Las Vegas, gained the lead during pit stops at Lap 100 as a result of a debris caution. There have been nine lead changes in the race.
During a competition caution thrown on Lap 31, pole-sitter Kurt Busch was caught speeding on pit road and restarted from the rear of the field. The No. 41 led the first 31 laps.
Kenseth had an unscheduled pit stop around Lap 75 for a bad vibration, but pit stops a few laps later enabled the No. 20 to get back to the front.
There’s been only two cautions in the first 134 laps, a competition yellow at Lap 30 and a debris caution on Lap 99.
The start of the race was delayed 23 minutes for a brief bout of rain.