Rory Kinnear and Adrian Lester shared the best actor honours at the Evening Standard theatre awards for their performances in the National Theatre's production of Othello.
The pair, who played Iago and Othello respectively in the Shakespearean tragedy, saw off competition from Chiwetel Ejiofor, who was nominated for his role in A Season In The Congo.
But Rory lost out in the race for most promising playwright to R achel De-lahay, who won for her drama about immigration and multicultural London, Routes.
Dame Helen Mirren was named best actress for her performance as the Queen in The Audience - P eter Morgan's play about the monarch's weekly meetings with her prime ministers.
Lucy Kirkwood's Chimerica was named as Best Play, Little Britain star David Walliams took home the comedy award for his performance as Bottom in A Midsummer Night's Dream and Hollywood star Kevin Spacey, who has been artistic director of the Old Vic since 2003, was given a special award for his contribution to British theatre.
Downton Abbey star Dame Maggie Smith was presented with a theatre icon award by Kristin Scott Thomas.
Andrew Lloyd Webber, whose new musical inspired by the Profumo affair opens in the West End next month, received a special award for his work in musical theatre.
Actress and writer Cush Jumbo won the emerging talent award for her one-woman show about the dancer Josephine Baker, and American actor Seth Numrich took home the award for outstanding newcomer for his turn as a small-town gigolo in Tennessee Williams's Sweet Bird Of Youth at the Old Vic op posite Kim Cattrall.
The paper's editor Sarah Sands said: "The high level of theatrical daring and creativity seen on the London stage this year made our choices tougher than ever to make. We, like the rest of the world, have been dazzled by the talent on show. It feels important for London's paper to celebrate this significant sector that spills over into other areas of cultural life."
Among the guests at the event at the Savoy Hotel in central London were Jude Law and Sir David Attenborough. The awards, now in their 59th year, were hosted by Homeland star Damian Lewis.