While speaking with "Today" host Hoda Kotb in his first television interview following the accident, the comedian recalled the horrific car fire, and detailed his severe burn injuries and intense recovery process.
Leno -- a vintage car aficionado -- said he was in his garage working on a 1907 White Steam Car with his longtime friend Dave Killackey. "The fuel line was clogged so I was underneath it," he told Kotb. "I said, 'Blow some air through the line.'"
"And suddenly, boom, I got a face full of gas. And then the pilot light jumped and my face caught on fire," he continued. "And I said to my friend, I said, 'Dave, I’m on fire.' And Dave’s like, 'All right.' I said, 'No, Dave, I’m on fire!"
Killackey told Kotb that he "couldn't even see [Leno's] face," adding, "He downplays it all, but I'm telling you, he was really engulfed. It was a wall of fire."
Killackey sprung into action to help. "I just grabbed him," he recalled. "He was just under the car. I grabbed him by the head, and I pulled his head into my chest."
"I thought it was a bad Tinder date," Leno joked, chiming in. "I thought, 'What’s going on here?'"
Killackey said he "put the car out" and told Leno to go to the bathroom and splash his face with cold water. "I went into the bathroom to look at Jay ... he downplays that, but it was horrific," he added. "It was a scary thing. It doesn't take a genius to figure out, 'Call 911' and that's what I did."
Despite his injuries, Leno said he drove home, noting that his wife Mavis of over 40 years "doesn't drive anymore" and he "didn't want her stuck" and wanted her to "know what was going on."
The TV host -- who suffered burns on his face, chest and hands -- went on to spend nine days at the Grossman Burn Center at West Hills Hospital in Los Angeles, where doctors had to "scrape off layers of burned skin," said Kotb.
Leno's surgeon, Dr. Peter Grossman, recalled to People, "When he came in, his burns were deeper than I anticipated. Jay is definitely an outlier in terms of how well he's healed considering the severity of his injuries."
However, "The Tonight Show" alum managed to maintain a sense of humor and a positive attitude throughout the whole thing, even cracking jokes during his interview with Kotb.
Even she asked if he was "worried" about his appearance following the accident, Leno quipped, "When you look like me, you don’t really worry about what you look like. Look, if I'm George Clooney it’s going to be a huge problem, but they said it would be all right, so my attitude is I trust people who are the best to do what they do."
Speaking more about his injuries, Leno -- who underwent two skin grafting surgeries -- said his ear and the side of his face had to be reconstructed. His hands and fingers also "got burned pretty bad," as he said.
The actor said that one part of his recovery included spending eight hours a day in a hyperbaric chamber, which is full of 100% oxygen that helps speed up healing.
"It's basically a glass coffin. They seal it," Leno said, jokingly adding that laying in the chamber "made me laugh" due to the fact that people couldn't hear him on the outside.
As noted by People and "Today," Leno was offered pain medication, but declined.