Film fans lined the red carpet in London's West End to see Robert De Niro and Al Pacino together at the premiere of their new film Righteous Kill.
The legendary actors have only shared one scene together previously, in 1995's heist classic Heat, while they were never onscreen at the same time in 1974's The Godfather II.
However, in Jon Avnet's Righteous Kill, cinema aficionados have the chance to see the pair as veteran New York City detectives who look to reveal the connection between a serial killer and a case they solved several years before.
"I wish we'd done it sooner," De Niro told the BBC of working with Pacino.
"I hope it won't take this long for us to do another project," he added.
"I'd hope we'd do another one or two more at least, we've always had a great respect for each other."
Pacino, meanwhile, admitted that the level of pressure on their partnership "makes you think twice".
"It was Bob [De Niro] who got me into the movie. We've known each other a long time, we're both New Yorkers and have seen each other over the years so there was a comfort level on set."
He added: "I hope we do another picture together, we're thinking about that down the line and I see that people want to see it and that's good to know."
Righteous Kill, also starring Carla Gugino and Curtis Jackson, is released on September 25th.