Two of the greatest winners in pro sports couldn't pull it off today ... with Peyton Manning and Tiger Woods LOSING a PGA Pro-Am to a team led by Phil Mickelson.
Tiger and Peyton (and 2 other guys) were teamed up at The Memorial Pro-Am Tournament in Dublin, Ohio on Wednesday ... where they faced off with Phil's foursome.
PGA officials tell us ... Tiger's team finished 2 under par -- while Phil's team finished 7 under.
Still, both Tiger and Peyton hit some pretty decent shots during the tourney ... and Tiger even gave away one of his golf balls to a little girl in the crowd!
Don't worry fellas ... only 364 days until the rematch.