The beloved TV and movie veteran's face appeared to be swollen as she arrived on the Broadway red carpet, and even posed for photos.
Many photographers feared she was suffering from an allergic reaction - or something more serious, but it has emerged she simply tripped over her Golden Retriever as she was leaving home earlier in the evening.
An insider tells WENN, "She's such a trooper. She tripped over her dog and took a really bad fall, but insisted on being there for her friend."
Moore has battled diabetes since the late 1960s and alcoholism. Earlier this year (11) she underwent elective brain surgery to remove a benign tumour.
Just last week (ends09Sep11), she was named the recipient of the 2011 Screen Actors Guild Life Achievement Award.
The actress, who is best known for her portrayal of homemaker Laura Petrie in The Dick Van Dyke Show and as title character Mary Richards in iconic sitcom The Mary Tyler Moore Show, will be the 48th person to pick up the accolade when the Screen Actors Guild Awards take place in January (12).