Graham Norton paid tribute to Sir Terry Wogan as the ninth performer took to the Eurovision stage.
The host said the contest was "bittersweet" for him because it is the first since the death of Sir Terry.
He added: "Eight years ago, when I was lucky enough to get this job of commentating, Sir Terry very kindly and graciously phoned me, and the only bit of advice he had for me was 'Don't have a drink before song nine'.
"Well this is song nine."
He added: "So while the crowd here in the Globe Arena cheer on their home boy, I would urge you back in the UK at home to raise a cup, a mug, a glass, whatever you have in front of you, and give thanks for the man who was, and always will be, the voice of Eurovision, Sir Terry Wogan. Sir Terry, this is song nine."
Celebrities and fans watching the show posted messages online, saying they too were raising a glass to the much-loved star.