On ABC's Jimmy Kimmel Live, Kimmel gave his version of where everything went awry. But Oscar-nominated Washington saved the Academy Awards by politely asking Kimmel and Warren Beatty to be quiet.
As Faye Dunaway accidentally announced that La La Land was the best picture winner instead of Moonlight, Beatty explained to the audience the reason for the mistake was due to the pair being given the wrong envelope backstage.
Kimmel leapt into the situation with his cheeky one-liners to keep the crowd laughing. But as Kimmel kept trying to make light of the embarrassing gaffe, Washington yelled at them from his seat in the audience, calling out: "Barry."
Kimmel said he realised that while he was talking, the Moonlight team and their director Barry Jenkins were behind him.
"Thank God Denzel was there to make sense," he said.
"I see Denzel Washington in the front row trying to get my attention. He's gesturing and he's pointing, I don't know what he's pointing, but he yells, "Barry," he said.
He said that Washington's reference to "Barry" initially confused him, and it was not until the two-time Oscar winner repeated himself that Kimmel figured out what he was trying to tell him.
"I realised that Barry Jenkins, the director of Moonlight, is standing behind me and Denzel wants me to get him to the microphone to make a speech," said Kimmel.
"So I listened to Denzel, as you should, and I went and I got Barry. Then everyone just stood there kind of shell shocked," he said. "And I ended the show."
"So Moonlight was the best picture, and now we have the producers of two movies on stage - and who the hell even knows who is who from which movie - and I'm just standing there like an idiot feeling bad for these guys," Kimmel recalled.
"I don't know if you know this, but I hosted the Oscars last night ... Except for the end it was a lot of fun," he said as he opened his show.
"We were chugging along and then all of sudden it turned into a one of those Maury Povich paternity test shows. It was the weirdest TV finale since Lost."
Kimmel said the incident, for which accounting firm PricewaterhouseCoopers took the blame, was as surreal for him as it was for everyone in the audience and the billions watching around the world.
"The plan is for me to end the show from the audience in a seat next to Matt Damon, who I want to make no mistake about whatever confusion there was about who won, Matt Damon lost," Kimmel said of the actor he poked fun at throughout the night.
I wrote the ending of the academy awards 2017. @jimmykimmel we really got them!
So we're sitting there and you just kind of figure, 'oh, you know, the host will go on stage and clear this up' and then I remember 'oh I am the host.'"
Kimmel said he thought of telling La La Land producers to run out with the award as confusion reigned as to what was going on, he was "standing there like an idiot feeling bad for these guys, but also trying really hard not to laugh".
A backstage chat with Warren Beatty, who opened the wrong envelope, revealed to Kimmel what went down.
"When you do a show like this you're not just a host, you're also the lead detective," he said. "Warren Beatty could be in prison right now if I wanted."
Known for his gags, Kimmel said people came up to him after the ceremony and asked if he was responsible for the stuff-up.
"If I pulled a prank, by the way, I wouldn't have just had the wrong winners in the envelope when they opened it there would have been a 'Bed, Bath, and Beyond' coupon," he said.
PricewaterhouseCoopers later apologised for the mix-up.
"We sincerely apologise to Moonlight, La La Land, Warren Beatty, Faye Dunaway, and Oscar viewers for the error that was made during the award announcement for best picture," the company said in a statement.