An oddball combination of mud and fire abruptly ended Dale Earnhardt Jr.'s reign as NASCAR Sprint Cup Series points leader Monday morning during the rain-delayed Duck Commander 500 at Texas Motor Speedway.

The 2014 Daytona 500 champion and series leader after four of the season's first six races, Junior crashed and burned on Lap 13 around TMS' high-banked, 1.5-mile quad-oval. Junior was trailing Aric Almirola's No. 43 Eckrich Ford Fusion when he clipped the grass on the inside apron of the frontstretch. The left-front splitter of Junior's No. 88 National Guard Chevrolet SS dug deeply into the mud, and the resulting blown left-front tire shot the car across the track and careening into the outside wall. That right-side impact caused a flash fire as Junior scrambled to safety.

Junior said he thought he was taking a “decent line” through the track's signature dogleg, as he and Almirola were attempting to pass Sunoco Rookie of the Year contender Kyle Larson.

"Just didn't see the grass,” said Junior, who started 19th. “Didn't know the grass was down there. With the way the A-post is on these cars you can't really see that good to that angle. I just didn't have a good visual of where the apron and the grass was and got down in there pretty good. You can't run through there the way they have these cars on the ground like that. Just a mistake on my part. Just misjudged it."

The race had just gone green after the opening 10 laps were run under a competition yellow -- a bow to a damp racing surface. "It was no factor,” Junior said.”I just made a mistake."

Four-time Sprint Cup champion Jeff Gordon, whose second-place finish to Joey Logano of Penske Racing gave him the points lead, said the opening sequence was just weird.

“When we left pit road at the beginning of the race, we drove by the two jet dryers, casually going by it,” said Gordon, driver of the No. 24 Axalta / Texas A&M School of Engineering Chevy. “The last one about blew all of us over. I mean, I thought it damaged my car as well. It got my attention. We all started avoiding that one.”

Junior had logged four top-three finishes during the season's first six races en route to a nine-point lead (227-218) over Matt Kenseth of Joe Gibbs Racing when the day began. Junior placed 43rd on Monday and exited Texas in sixth, 31 points behind his Hendrick Motorsports teammate Gordon, who leads Kenseth by four points (259-255) heading into the Bojangles' Southern 500 at Darlington Raceway Saturday night.