British star Lesley Manville and American actor John Lithgow have won the acting categories at this year's Olivier Awards, which recognise excellence in London theatre.
Lithgow, 79, played Roald Dahl in Giant, which is about the children's author wondering whether to make a public apology.
While accepting his award he appeared to reference the current controversy over Donald Trump's second term as US president.
The Conclave star quipped: "It's not always easy to welcome an American into your midst, and at this particular moment, it's probably a little more complicated than usual."
He also told the audience at the Royal Albert Hall that the "special relationship is still firmly intact", despite Mr Trump imposing tariffs on British exports to the US.
His co-star, English actor Elliot Levey, took best actor in a supporting role.
Giant was also named best new play.
Manville, 69, was honoured for her performance in the Greek tragedy Oedipus at the Wyndham's Theatre.
She said she felt "emotional" while accepting her statuette because it was a production she had "felt very strongly about being" in.
Manville, who played Princess Margaret in The Crown, added that she was taking an early flight to Dublin on Monday to do some filming, and would not be getting "much sleep tonight".
Best actress in a supporting role went to Romola Garai for her performance in The Years, based on a memoir by French writer Annie Ernaux.
Garai, whose film credits include Scoop and Atonement, was nominated in the same category for Giant.
Dame Imelda Staunton won a fifth Olivier, for best actress in a musical for the London revival of classic musical Hello, Dolly!
The Curious Case Of Benjamin Button won best new musical, a best actor musical award for Lark Rise To Candleford actor John Dagleish, and the outstanding musical contribution award.
The annual event was co-hosted by British singer Beverley Knight and Pose star Billy Porter.