Kurt Busch won at Texas Motor Speedway on Sunday, taking over the lead with 2½ laps left when his younger brother's car suddenly slowed on the backstretch after leading 232 of the 334 laps.
Johnson, the series points leader trying to become the first Sprint Cup driver to win four consecutive season championships, wrecked on the third lap.
His crew needed more than an hour to repair and basically rebuild his No. 48 Chevrolet, but he returned to finish 38th -- 129 laps behind Kurt Busch. Johnson's points lead was cut from 184 to 73 over Hendrick teammate Mark Martin, who finished fourth, with two races left.
"It's still a respectable lead, 73 with two to go is a good position to be in," Johnson said. "I hate we gave up all these points. ... It's not as bad as it could have been, we could have finished 43rd."
Kyle Busch won the Nationwide and Camping World Truck races at Texas, and was trying to become the first driver to win in all three of NASCAR's national series on the same weekend. It was the 28th time he ran all three races the same weekend.
"This is the first time Kyle and I raced each other hard," said Kurt Busch, who led six times for 89 laps while also running second behind his brother much of the race. "It's bittersweet, I was rooting for him, but at the same time this is for us. "
Kurt Busch got his second victory of the season in the No. 2 Dodge, and 20th of his career, with an average speed of 147.137 mph. Denny Hamlin finished a distant second, 25.686 seconds behind, and Matt Kenseth was third.
Jeff Gordon, another Hendrick driver who is third in points, finished 13th after avoiding serious problems of his own. He cut his points deficit to Johnson from 192 to 112 points, though lost ground on Martin.
Kyle Busch had trouble refiring his car after his splash and dash stop and wound up 11th.
Dave Rogers, who made his debut as Kyle Busch's crew chief in Sprint Cup, said they thought they had enough fuel to finish the race and described the driver as "frustrated." Busch didn't talk to reporters.
Coming out of Turn 2 on the third lap, Sam Hornish got loose after apparently being tapped by David Reutimann. Hornish made contact with Johnson, who scraped the outside wall. It looked as if Johnson might save his car before he was hit again by Hornish, then slammed into the inside wall.
Johnson returned to the track on lap 115, the front and rear of his car solid black after all the repairs. The front and rear suspensions and the driveshaft had been replaced, along with other repairs. Crew members from the teams of Gordon and Dale Earnhardt Jr. assisted in what looked like a makeshift body shop in the garage.
After finishing second at Texas in April, behind Gordon, Johnson had another disappointing fall race at Texas while trying to close out a championship.
Last November, Johnson struggled to 15th while Carl Edwards gambled on fuel and won by a wide margin. Johnson left Texas with a 106-point lead in the chase last year, and won by 69 over Edwards.
Gordon avoided serious trouble in the second turn on lap 175, spinning but not hitting anything after Juan Pablo Montoya and Edwards made contact and spun ahead of him going onto the backstretch.
When Gordon turned down to avoid the other cars, he spun himself. He ended up with flat tires and a broken brace and came into the pit before it was opened, incurring the penalty that made him restart at the back of the field. He was still in 18th place, where he was at the time of the accident, when the race restarted.
REMEMBERING FORT HOOD
Fort Hood soldiers played a prominent role in NASCAR's prerace ceremonies just 170 miles from the site of shootings that left 13 dead at the Army post.
There were 40 Fort Hood soldiers displaying the American flag during the national anthem Sunday. The number was supposed to be 45, but track officials said five soldiers scheduled to attend were among the 29 injured in Thursday's attack.
A moment of silence was observed for the fourth time during the weekend. The other observances came during the Nationwide and truck series races, and Sprint Cup qualifying.
A U.S. Army logo with the words "God Bless Our Fort Hood Troops" was painted on the infield grass Friday.