Debra Messing showed off her impeccable sense of style as she was joined by Robert De Niro at the afterparty for their latest movie, The Alto Knights, in London on Thursday. 

The American actress, 56, cut a glamorous figure in a classy black strapless ballgown featuring a subtle pattern.

She added inches to her frame with pointed black court heels and styled her brunette tresses in a voluminous blowout. 

Debra exuded Hollywood glamour as she accessorised with a sparkling silver choker necklace paired with matching droplet earrings. 

The beauty took the time to pose for selfies with fans and sign autographs as they all waited for her arrival. 

Meanwhile, Robert, 81, looked sharp in a grey turtleneck, black coat, and matching tailored trousers. 

Debra Messing, 56, cut a glamorous figure in a classy black strapless ballgown as she attended the afterparty for her latest movie, The Alto Knights, in London on Thursday

The American actress was also joined by Robert De Niro, 81, who looked sharp in a grey turtleneck, black coat, and matching tailored trousers

He completed his look with yellow-tinted glᴀsses and sported a pair of smart shoes. 

Lines of fans gathered in a bid to get autographs from Robert as he got flanked by security while exiting the venue. 

Based on true events, the movie is set in 1950s New York, with two-time Oscar winner Robert portraying two roles – rival Italian-American mafia bosses Frank Costello and Vito Genovese.

Meanwhile, Debra will star as Costello’s wife Bobbie, in the upcoming thriller movie.

At times adapting a documentary film-style approach, The Alto Knights recounts the old friends’ shared past, the events leading to their rift and a failed ᴀssᴀssination attempt on Costello.

Their power struggle plays out in tense scenes, some of which see Costello and Genovese clash face-to-face.

The movie is directed by Rain Man, Good Morning, Vietnam and Wag the Dog filmmaker Barry Levinson and written by Nicholas Pileggi, known for Goodfellas and Casino.

It is produced by De Niro’s long-time collaborator Irwin Winkler, and the actor said working with the trio convinced him to return to the mobster genre.

For the glitzy bash, Debra teamed her chic ensemble with pointed black court heels and styled her brunette tresses in a voluminous blowout

She exuded Hollywood glamour as she accessorised with a sparkling silver choker necklace paired with matching droplet earrings

The actress completed her look with a radiant palette of makeup and looked in great spirits as she arrived at the venue

She took the time to pose for selfies with fans and sign autographs as they all waited for her arrival

However, the star was soon joined by members of her security team as huge crowds of fans swarmed to try and get her autograph 

Read More Glamorous Debra Messing links arms with Robert De Niro as they attend the London premiere of their new movie The Alto Knights

‘I wasn’t planning on going back to it, but when Irwin Winkler sent me the script, I said ‘let me consider,’ Robert said at the movie’s London premiere on Thursday.

‘When we were talking about who’d play the other part, they wanted me for Costello, he (Winkler) said ‘Well, what about if you play the other part?’ I said ‘That’s an even better reason to do this, if I do it,’ the actor added.

Irwin, 93, said he couldn’t think of anyone else better suited for the roles.

‘We didn’t do it with any visual effects. It was all really makeup and just him,’ Irwin said.

‘Even after seeing the film so many times, I see two different characters. I don’t see one man playing them.’

Robert enlisted a co-star to act out scenes featuring both of his characters.

Meanwhile, two-time Oscar winner Robert, layered up from the cold with a grey and black striped scarf as he arrived at the venue with his security

He completed his look with yellow-tinted glᴀsses and sported a pair of smart shoes as he was greeted by fans

Based on true events, the movie is set in 1950s New York, with two-time Oscar winner Robert portraying two roles – rival Italian-American mafia bosses Frank Costello and Vito Genovese

He said: ‘I settled on one guy I thought would be good. He played the Gambino part, and he learned both parts. So, I did it with him, and he was a tremendous help.’

As well as Debra playing Costello’s wife, Shogun actor Cosmo Jarvis portrays gangster Vincent Gigante.

When asked if the experience had inspired him to challenge himself further, Robert, who has several movie projects lined up, said: ‘Now I’m just trying to keep up with everything I’m doing.’

The Alto Knights’ begins its global cinematic rollout on March 19.