Hamlin was able to climb out of the car on his own, but he immediately went down. He was airlifted to local hospital for observation. He spent the night at Loma Linda University Medical Center. Hamlin was diagnosed with a fractured L1 vertebra.

He was released on Monday — and walked out of the hospital under his own power — and was allowed to fly home.

Dr. Jerry Petty of Carolina Neurosurgery & Spine Associates evaluated Hamlin. Joe Gibbs Racing issued the following statement on its Facebook page:

Dr. Petty determined that Hamlin will not require surgery, but will need time to properly heal, which is estimated around six weeks time. Dr. Petty will make the determination when Hamlin will be able to return to racing this season. No decision has been made on a replacement driver for Hamlin during his absence from the NASCAR Sprint Cup Series.

This news effectively ends Hamlin’s chances to win the Sprint Cup Series championship.

After his release from the hospital, Hamlin said he knew he was in trouble because he felt his back pop after the violent collision. He said he couldn’t breathe and is still having difficulty breathing.

Hamlin said that Logano has not reached out to him. He added that he made sure to give Logano plenty of room. But, he said:

I think he saw I was going to win and wasn’t going to let that happen.

For his part, Logano said:

I just thought we were racing hard, you know? It happens. You don’t ever want anyone to get hurt; you don’t ever want anything to happen, especially to Denny. We were racing really hard there at the end of the race. I wish there was a SAFER barrier down there, and I wish I knew before I made any comments on TV also.

Following the race Logano said:

He probably shouldn’t have done what he did last week (at Bristol), so that’s what he gets.

He later said he didn’t try to wreck Hamlin in “any way, shape, or form.”

Kerry Tharp, NASCAR Director of Communications, tweeted that “NASCAR will issue no penalties from last weekend’s events at [Auto Club Speedway].

While no announcement has been made as to a replacement, Elliott Sadler, who drives for JGR in the Nationwide Series, seems like a logical choice to replace Hamlin.

After raindrops slowed the race on Lap 124, Stewart, the race leader, faked a move toward pit road but stayed on the track and matched the pace car’s speed of 65 mph, a far cry from the lightning-fast laps he ran under the green flag.

But that move — staying out and running slow caution laps before NASCAR stopped the race on Lap 129 — proved decisive for the defending NASCAR Sprint Cup champion, who claimed his second victory of the season, his second at Fontana and the 46th of his career, tying him with Buck Baker for 14th on the career victory list.

Kyle Busch, who stayed out with Stewart, finished second, with Dale Earnhardt Jr., Kevin Harvick and Carl Edwards completing the top five.

Greg Biffle ran sixth, followed by Ryan Newman, Martin Truex Jr. and Kurt Busch, all of whom gambled on protracted rain and stayed on the track during the initial shower. Jimmie Johnson and polesitter Denny Hamlin came to pit road and finished 10th and 11th, respectively.

“I don’t think that I faked him out,” Stewart said of Hamlin. “I’m sure he had made his decision already — looked good, though.”

Never before has Stewart won two Cup races this early in a season. Stewart was at a loss for an explanation.

“I don’t know, but I like it,” he said. “I’m really proud of (crew chief) Steve Addington and all of our guys. This Office Depot Chevy was bad fast.”

In Johnson’s case, the top-10 was a godsend, given that the No. 48 Chevrolet developed an oil line problem as the cars circled the two-mile track under caution. Johnson’s car began smoking and he kept it rolling on the apron until NASCAR stopped the race.

The event ran caution-free for 124 laps, until rain in Turns 3 and 4 brought out the first yellow flag of the afternoon. Stewart had retained the lead through a third cycle of green-flag pit stops, with Hamlin chasing him.

Hamlin had made a run at the leader when the rain began to fall, but he and Johnson opted to give up positions in the top five and come to pit road, after Stewart made his feint toward the pits but remained on the racetrack.

Feint or not, Hamlin was committed to the trip to pit road, and he explained the decision.

“We were planning on the race going back to green, and if it doesn’t, we’ll lose some spots, but if we chose to stay out there, we would have to be behind all the cars that pitted (if the race restarted),” Hamlin said as the rain intensified. “(In that case), your chance of winning decreases greatly.

“So you could give up a few spots if it finishes up here and lose a chance to win in the grand scheme of things . . . We had finally gotten to (Stewart’s) bumper when the rain came.”

That left Busch in second place. The driver of the No. 18 Toyota had led 80 laps to that point, but Busch had rubbed the wall in traffic before the halfway point, and the handling of his car deteriorated thereafter.

Busch wasn’t dismayed that the race ended when it did.

“I wish we would have been able to race the whole thing, on the one hand,” he said, “but, on the other hand, I’m kind of glad we’re not, because we have a little bit of damage that slowed us down there . . .

“Trying to run back with Stewart’s lap times, that’s when I was trying too hard, too close to the fence, got myself in trouble there — caught the right side a little bit.”

Notes: Biffle retained the series lead, seven points ahead of second-place Harvick . . . Earnhardt’s third-place finish elevated him to third in the standings, 17 points back of Biffle and one ahead of Stewart in fourth.