Quinta appeared on Jimmy's show Wednesday night, and he effusively expressed his regrets for overshadowing Quinta, who snagged a trophy for Outstanding Writing for a Comedy Series.

As you know, Will Arnett dragged Jimmy out onstage as Kimmel pretended he was passed-out drunk and he lay there as Will read the noms, announced Quinta as the winner and while Quinta gave her acceptance speech.

Jimmy was ready from the jump for a big mea culpa. As soon as Quinta sat down on the couch, Jimmy went right into apology mode ... "it was a dumb comedy bit that we thought would be funny." In other words, he's now in on the non-joke.

Then Jimmy joked..."I lost, and then I drank too much, and I had to be dragged out on the stage. And then people got upset. They said that I stole your moment, and maybe I did. I'm very sorry if I did do that — I'm sorry I did do that, actually."

Quinta was more than gracious, essentially saying it didn't bother her ..."I was honestly in such a moment of having a good time, like I won my first Emmy! I was up there happy, and I was wrapped up in the moment."

Fact is ... Quinta and Jimmy have history. He was an early supporter of her, bringing her on his show and singing her praises.