Jennifer Hudson Honors Whitney Houston at Grammy party with 'Greatest Love of All'

Jennifer Hudson brought the house down at Clive Davis's pre-Grammy party Saturday night, with a rendition of "Greatest Love of All" that would have surely left Whitney Houston impressed.

Kevin Costner, Whitney's "The Bodyguard" co-star, hopped on stage with a super emotional tribute to both Whitney and Clive. Speaking to Davis from the stage, Costner said, "Neither one of us, in the end, could protect your beloved Whitney."

Costner went on ... "But your fingerprints on her life are clean my friend. You were a miracle in her life. Thank you for being her bodyguard, Clive. Everyone in this business has a mom, but not everyone has a Clive."

TMZ broke the story ... Whitney died of an overdose at the Beverly Hilton hotel back in 2012, just hours before Clive Davis's annual pre-Grammy bash.