Robert De Niro and Sylvester Stallone in Grudge Match.

Grudge Match should’ve been really fun. Sylvester Stallone and Robert De Niro—riffing on their iconic boxing characters Rocky Balboa and Jake LaMotta—have one last boxing match. It’s a setup for something great, nostalgic and even funny. Instead, director Peter Segal manages to make this undertaking a morose, unfunny slog.

Stallone plays a generally unhappy character, while De Niro plays a total asshole. Their characters wind up in a scenario that gets their near-70-year-old bodies into the ring for a rematch 30 years after their last fight. The fight itself is OK, with both men looking pretty fit for their age. However, everything leading up to the fight is oddly paced, and sometimes painful to watch, especially when Kim Basinger is onscreen as a confused love interest. Alan Arkin and Kevin Hart are wasted in supporting roles.

This seemed like a sure thing, but Segal blew it. The film takes itself too seriously, and it doesn’t know when to smile.

Grudge Match is playing at theaters across the valley.