Forget who lifts the famous Eurovision microphone trophy, the real winner has already been crowned. Hannah Waddingham, the star of Ted Lasso and Sex Education, is better known in the US than the UK – but perhaps not for much longer. The London-born actor has wowed viewers of this week’s Eurovision semi-finals, presenting alongside Britain’s Got Talent’s Alesha Dixon and the Ukrainian singer-songwriter Julia Sanina. Reviewers have gushed over Waddingham’s “easy chemistry, smooth patter and willingness to join in the silliness”, while her impromptu dance moves, exuberant facial expressions and linguistic skills have spawned thousands of internet memes. She had the crowd in Liverpool Arena chanting her name after reciting the Eurovision rules in fluent French before adding: “You see, Europe, some of us Brits do bother to learn another language.” The BBC presenter Nina Warhurst told the corporation’s Eurovisioncast podcast: “I think we have an overnight national treasure on our hands. Hannah Waddingham is the absolute bomb.” Warhurst said the co-host “looks like she’s having the time of her life” and combines the “sort of Eurovision schmaltz with a humorous side-eye but extraordinary warmth as well”. Waddingham is no stranger to the stage but many viewers would be forgiven for not being aware of her before this week. She has been a leading lady in London’s West End and Broadway for more than 20 years but had played mainly bit parts on screen – such as Tonya Dyke in Benidorm and an adult film star in the BBC’s Not Going Out – before finding wider fame via Game of Thrones, which she joined in season five, and more recently Ted Lasso and Sex Education. Waddingham hosted last month’s Olivier awards – her presenting debut – to similarly rave reviews. But Eurovision, with more than 160 million viewers, catapults her to a new level of stardom. She will fulfil a childhood dream when she hosts the grand final alongside the Eurovision favourite Graham Norton. The prospect of announcing the winner “literally gives me shivers of excitement”, she told the BBC’s Eurovisioncast this month. “My 12-year-old self couldn’t believe that I would ever be saying [it].” Paul Jordan, 39, a Eurovision expert who has attended almost every contest since 2000, said Waddingham was not a complete unknown but her fame – until now – was a case of “those who know, know”. “This is the first time it’s proper mainstream,” he said. “There will be about 10 or 12 million people watching her [in the UK] and I think people are going to be really endeared.” Jordan, a former communications official for Eurovision, said Waddingham “outshines every other person on that stage” and had three characteristics that made a perfect co-host: heart, warmth and fun. He added: “She’s endearing herself to new audiences and I really hope we get to see more of her because she’s funny, she’s a good presenter, she can sing, she can act. There’s not really anything she can’t do. “If her career goes to bigger and bigger things because of this, it will be thoroughly deserved, and it was an inspired choice to choose her.”