Brigitte Nielsen Opens Up About Reuniting with Ex-Husband Sylvester Stallone for 'Creed II' : 'We Were Professionals'

For Brigitte Nielsen stepping onto the set of Creed II for the first day of filming was "incredibly emotional."

"My heart was beating very fast," the Danish actress, 55, tells PEOPLE.

To return to the role of villainous Ludmilla Drago, 33 years after first playing her in 1985's Rocky IV, Nielsen reunited with ex-husband Sylvester Stallone. The pair famously wed in 1985 but divorced two years later amid plenty of tabloid headlines.

"In 1985 I was married to Sylvester and this time I am the ex-wife," says Nielsen. "But it was wonderful to have half of the cast there 32 years later. Who could have ever dreamed that you pick up the same roles many years after?"

She adds there was no drama between her and Stallone, calling the opportunity to work with him again "amazing."

"We are two professionals and we kept it that way," she says. "He stayed in the American corner and I stayed in the Russian corner. We were on opposite sides but it was pleasant."

The sequel, which arrived three years after the release of the first Creed film, once again centers on Michael B. Jordan who reprises his role as Adonis Johnson — the newly crowned heavyweight champion who is under the tutelage of Rocky Balboa, played by Stallone.

Nielsen had yet another reason for being emotional while filming Creed II. She was seven-months pregnant at the time and kept it a secret from the cast and crew.

"I was so nervous and I was trying to hide it in my ivory suit, which we did," she says. "It was a very first big day."

After more than 10 years of trying to conceive through in vitro fertilization, the actress shocked the world when she gave birth on June 22 at age 54 to her baby girl, Frida, with her Italian model husband Mattia Dessi, 40.

Although initially able to keep her pregnancy under wraps, when she returned to the set three weeks later she was no longer able to hide her growing baby bump. Instead, the director, Steven Caple Jr., used a little movie magic to help her character conceal her pregnancy. "We pulled it off and everyone was happy," she says.

The actress is currently spending the holidays in Europe with her husband and daughter and says this past year has given her many reasons to be grateful.

"2018 has given me the best of everything — a beautiful daughter, we are healthy, we are happy and my career is moving forward. One cannot ask for anything more," she says. "We have been shedding a lot of happy tears."