The show will be broadcast on BBC One and hosted by Graham Norton, with the victor expected to be announced at 11.35pm this evening.
"SuRie may be looking to win the UK's first Eurovision crown in 21 years but it would be against all the odds as a 200/1 outsider and the 2/1 favourite to finish last, with a first half draw not helping what has in recent years become a tough night for the United Kingdom". If that isn't wonderful, I don't know what is.
The incident left SuRie without a microphone for at least ten seconds and she was forced to clap along as cameras cut to fans in the audience.
Twenty-six nations are vying for the Eurovision 2018 title.
Cyprus and Israel are among the favourites to clinch this year's Eurovision 2018 song contest, which begins at 8pm GMT tonight.
The show, watched by millions around the world, got underway at the riverside Altice Arena with performances by Portuguese fado stars Ana Moura and Mariza, a willowy singer with bleached blonde hair.
He put the room to Jamala, with whom she won the Eurovision in 2016.
The dress came to life with lighting displays and laser effects as she sung.
Britain will be represented SuRie, who will be singing "Storm" to an audience of more than 200 million people worldwide.
This year's final won't be seen in China though.
Ireland, which holds the record for the most Eurovision wins, made the final for the first time since 2013 for the track Together, which features a romantic dance between two male dancers and rainbow flags on the stage.
No country can vote for its own contestant.
"Cyprus have overtaken previous favourites Israel, with entrant Netta's unconvincing rehearsals performance of Toy seeing the entry drift before coming back into 3/1 second favouritism thanks to getting a highly advantageous second half slot in the draw".
Viewers and professional juries in all 43 participating countries will pick the victor, with televoting and juries each representing 50 percent of the outcome.