Almost immediately the 27-year-old's name began trending worldwide on Twitter and millions logged on to watch the accompanying music video online, which was released after a slick PR campaign maximised anticipation.
Many fans were also quick to praise her slimmer silhouette, which the Daily Mail can reveal was helped along by a special diet plan.
In interviews with Nick Grimshaw on Radio 1, Chris Evans on Radio 2, and on commercial stations including Magic, Capital and Heart FM she spoke about her life since her last music release, the title theme for Bond film Skyfall in 2012.
Adele described motherhood as "wonderful" and said being a mother was 'the main thing in her life' - but she had abandoned attempts to write an album about it because it was 'boring'.
She also made a point of referring to the father of her child Simon Konecki as her boyfriend, correcting reports they had married in secret.
She spoke about her desire to stay out of the limelight and said she finds fame "quite frightening" and "toxic". "It's very charming and it's very persuasive, but also it doesn't last," she added.
The star confirmed that fame, and her £50million (NZD$113m) fortune, had not changed her - saying the only difference in her life was that she now shops at Waitrose instead of Tesco and had bought a better television.
But she admitted nearly giving up on her third album, called 25, because she felt she had lost the ability to write lyrics. "I felt like I was never going to finish this record. I wanted to give up because I couldn't do it and I thought I'd run out of ideas and just lost my ability to write a song."
She persevered, however, and the resulting album - to be released on November 20 - and is likely to be a sure-fire success, if the reaction to her single is anything to go by.
Fans described it as "beautiful" and "incredible" and declared that the singer, who had vocal surgery in 2011, had "the voice of the century".
The singer looked radiant and healthy as she made whirlwind visits across London yesterday in a chic black outfit with mirrored heels.
The Mail can reveal that she followed a diet from food delivery service Pure Package to help stay in shape.
A source said: "She's a mum now and she has to keep her energy levels up but she has no interest in faddy diets or trying to be super skinny. But she's being very sensible and she's got herself a personal trainer too."
Diva who's coining it in
• £50m Adele's current fortune, twice that of the individual members of One Direction
• 30m copies her second album 21 sold globally since its release in 2011
• 4.75m copies of 21 sold in Britain, the fourth best-selling UK album of all time
• 6 Grammy Awards won in 2012 for 21, equalling Beyonce's record for the most awards won by a female artist in one night
• 210 Total number of weeks her albums have spent in the Top 40
• 1 Oscar for her title song for 2012 Bond film Skyfall - the only Bond theme to win an Academy Award
• 1m The number of Instagram followers she accumulated within 24 hours of opening her new social media account
• £1,000 the bonus she gave every worker, including interns and cleaners, at XL Recordings after 21 went seven times platinum in UK
- Daily Mail
