The pair was filming an energetic routine when dancer-turned-actress Hough lost her footing and ended up in a heap on the floor, and she admits she had to pinch herself when she found Cruise helping her back to her feet.
She tells People magazine, "He took care of me on set. He was making sure I was OK, and I was like, 'Somebody cares about me, and it's Tom Cruise!'"
But the Hollywood actor wasn't the only co-star Hough bonded with - she now also counts R&B superstar Mary J. Blige among her good pals.
She adds, "If I had to pick a soul-mate as a best friend, she would be my soul-mate. It's the oddest match: Mary J. Blige and Julianne Hough! But we became so close!"