Dozens of stars defied the sleet and wind to sashay down the red carpet for the awards, which are widely viewed as a bellwether for the Oscars on February 24.
The Baftas have picked the same best film as the Oscars for the past four years in a row, and for five of the past 10 years.
Veteran British actress Helen Mirren stole the show with freshly dyed pink hair, while US star Jennifer Lawrence blew a kiss to television audiences during the ceremony.
Les Miserables won the most awards with four including Hathaway's gong, plus technical prizes for production design, sound and hair and make-up, where it triumphed over the New Zealand production The Hobbit: An Unexpected Journey.
Riva's best actress award for her role as a dying woman in Amour - which won the Palme d'Or in Cannes last year - came after the movie by Austrian director Michael Haneke also won the best foreign language film award at the Baftas.
Glossing over his own Oscar snub, Affleck said the best director award was a second chance for him after a career that took off when he starred in the 1997 picture Good Will Hunting with Matt Damon.
"I want to say this is a second act for me and you've given me that, this industry has given me that and I want to thank you, and I'm so grateful and proud," he said as he accepted the award from Sir Ian McKellen.
Argo also won the top Golden Globe awards against all the odds, beating Lincoln.
Affleck also won the best director award from the Directors Guild of America a week ago. Argo has seven Oscar nominations, including best film.
Cult director Tarantino won the award for best original screenplay for Django Unchained and David O. Russell picked up the best adapted screenplay award for romantic comedy Silver Linings Playbook.
In a rare accolade for the James Bond series, Skyfall was named best British film and the score won the best original music prize. Skyfall is Britain's highest grossing film ever.
The Baftas ceremony ended with the awarding of a special fellowship to filmmaker Alan Parker, the director of movies including Midnight Express, Birdy, Angel Heart and Bugsy Malone.
- AAP