Greatest Day! Gary Barlow serenades an ecstatic Take That superfan for her 30th birthday after making a surprise appearance from the fire exit

Gary Barlow sent a superfan into a frenzy when he serenaded her on her 30th birthday in Dundee.

The Take That frontman dropped by on Saturday night to attend Jill Campbell's milestone birthday after she spent months campaigning for a visit from the star.

A video showed guests erupting with cheers as Gary entered the venue from the fire exit and began belting out Take That's 2008 hit, Greatest Day - as an ecstatic Jill stood just metres in front.

Gary Barlow sent superfan Jill Campbell into a frenzy when he serenaded her on her 30th birthday in Dundee on Saturday night 

The teacher from Broughty Ferry had admitted on the day before the event that she still wasn't sure if she had done enough.

But three campaign videos later, where Jill is shown frolicking around with a Gary cardboard cut out, she finally came face to face with the 45-year-old musician.

Surrounded by dozens of friends and family, the clip captures Jill looking completely astonished when Barlow appears.

Jill, who has been a fan for over 20 years, quickly hugs the pop star before holding her face in awe as he took to the mic and wishes her a happy birthday.

He then launches into the number-one pop track as party-goers swarm around him in delight.

Footage taken on a guest's mobile phone shows the former X Factor judge pumping the air with his fist as he works the crowd.

A video showed guests erupting with cheers as Gary entered the venue from the fire exit and began belting out Take That's 2008 hit, Greatest Day - as an ecstatic Jill stood just metres in front

Ever the charismatic performer, he even kisses one of the female guests on the cheek, causing the crowd to whoop even louder.

Before leaving, Gary took time to take photographs with Jill and her guests while wearing his trademark white shirt and black waistcoat.

After the event Jill posted a photo on Twitter showing her beaming as she hugged the vocalist.

She wrote alongside it: '@GaryBarlow so my HERO sang to me last night for my 30th. Thank u so much Gary you have made me the happiest girl.'

After Gary emerges from the fire exit of the party venue, Jill quickly hugs the pop star before holding her face in awe as he took to the mic and wishes her a happy birthday

Dozens of photographs and messages were later posted to Jill's Facebook page.

Melissa Bremner wrote: 'I am over the moon for you that all your hard work paid off and Gary came to your party. What a great memory you have for your 30.'

Jane Galloway said: 'So glad GB turned up tonight Jill. What a 30th to remember. You're wish came true.'

And Karen Ritchie wrote: 'I'm so pleased for you. You totally deserve it.'

The shock appearance comes several months after Jill and her loved ones began tweeting the star, using the hashtag Get Gary to Jill's 30th, urging him to come to the party.

Ecstatic: Jill posted this picture hugging the Take That frontman after the surprise appearance and wrote: 'Thank u so much Gary you have made me the happiest girl'

The persistent Scot created three campaign videos, one in which parodied Back for Good and showed Jill singing around different parts of her hometown.

She also changed the lyrics to relate to Dundee and enlisted the help of her sister to prance around in a Barlow face mask while she performed.

She sings: 'Got a picture of you in my bedroom, got your souvenirs from every show you've done, oh yeah.

'Went to London two or three times, to Dubai and Aberdeen. Now I think you should come and see me in Dundee.

'Whatever you do, I wanna see you, I really mean it, I just need you here in May.'

Guests at the event whipped out their phones to record the former X Factor judge's performance 

The mother-of-two had already planned to have a Take That themed party for her 30th but said that getting Barlow himself would be the ultimate birthday gift.

Speaking before the event Jill said: 'I've been a Take That Fan from day one, attending my first concert when I was eight in Aberdeen with my mum, sister and cousins. From then, my sister and I have been Take That addicts.

'I love him so much because he is the main pianist and vocalist in the band. He's the main songwriter and I admire his talent.

'Every time I see him I love him more.'

The appearance comes as Barlow posted  on Twitter back in March that he would consider surprising fans during milestone birthdays - having serenaded couples at their wedding in the past

The idea to campaign came after Barlow posted a social media video saying he would consider surprising fans during milestone birthdays - having serenaded couples at their wedding in the past.

Back in March he posted on Twitter: 'So... If you have a 'milestone' Birthday this year start your campaign now!

'21, 30, 40, 60, 110 !!!!! I'll come and sing at your party 'Good luck everyone ! Xx'

Last week, he also surprised another superfan, Jo Chapman, at her 40th birthday party in Maidstone, Kent.