The Best Actress honouree was being interviewed for a pre-taped segment on U.S. breakfast show Good Morning America shortly after her big win for Silver Linings Playbook when Nicholson stopped by to heap praise on the young actress.
He told her, "You did such a beautiful job (in the movie). I don't mean to crash your interview..." as Lawrence joked, "Yeah, you're being really rude!"
Nicholson then made a comment about how she bore a striking resemblance to an old flame of his, prompting the blonde beauty to reply, "Oh really? Do I look like a new girlfriend?".
The 22-year-old star, who split from her actor boyfriend Nicholas Hoult late last year (12), laughed as the veteran quipped, "I thought about it!", but Lawrence was soon regretting her risque behaviour as she gasped, "Oh my God" and buried her head in her hands as Nicholson, 75, walked away.
The whole encounter was caught on camera and aired on Tv on Monday morning (25Feb13).
The post-win run-in with Nicholson wasn't Lawrence's only embarrassing moment of the Oscars - she also tripped over her Dior couture dress and fell on the stage stairs as she made her to the podium to collect her Best Actress prize.