Diana Ross pulled out all the stops in the name of Oscar Sunday ... giving people in attendance at Byron Allen's annual gala a night of endless love.
The former Supremes singer was havin' a blast headlining Byron's shindig at the Beverly Wilshire Hotel, busting out some of her classics from the past 6 decades.
The 78-year-old icon performed for about an hour and had 3 costume changes over that period. Yes, Miss Ross still knows how to put on a show!
Believe it or not, Diana wasn't the only big event at this shindig -- attendees could also pay money, which went to Children's Hospital L.A., to get roasted by the famed roastmaster Jeff Ross -- and Chrissy Teigen's mom Vilailuck was one of the lucky donors.
Take a look, Jeff doesn't go easy on her, but we guess that's the best bang for your buck -- no pun intended. Howie Mandel MC'd the roast and threw in his 2 cents too.
Despite Jeff's harsh roasting of several folks who donated to the cause, not a single comedian was slapped!!!
All that AND Diana belting out her hits? An invite to this party was the second best thing you could win Sunday night.