Princess Eugenie dons disguise to watch Beyonce at London stadium without being spotted

The British royal joined the hardcore fans standing on the pitch

Engaged British royal Princess Eugenie put her hair up inside a black hat and managed to go incognito as she joined her fiancé, Jack Brooksbank, at the London Stadium on Friday night to see Beyonce and Jay-Z perform in their first London gig. Managing to go under the radar, Princess Beatrice's sister danced with her boyfriend with the rest of the 66,000-strong-crowd at the sell-out gig.

Beyonce performed at the London Stadium 

Looking just like a regular concert-goer, the princess, who is ninth in line to the throne, blended in with her pop crowd surroundings as she dressed down in a black jacket with her hair pulled up into a ponytail beneath her black bowler hat. According to onlookers, who shared a photograph of the low-key royal with the Daily Mail, Eugenie was boogying along to the music with everyone else in the crowd.

PHOTOS: Eugenie's colourful Trooping the Colour outfit

It's not the first time the princess has seen Beyonce play live - in fact she almost did a duet with her in 2013. The royal was sitting in the crowd to watch Beyonce play London's O2 arena in her Mrs Carter Show. She was in the crowd along with fellow concert-goers including Donna Air and James Middleton when the American superstar held the microphone out to her to sing a line from her hit song Irreplaceable. Perhaps suffering from stage fright, Eugenie declined the offer.

Princess Eugenie wears green in this year's Trooping the Colour

Princess Eugenie wasn't the only unexpected member of the audience at the London Stadium - also in attendance was Beyonce and Jay-Z's daughter Blue Ivy, 6, who was spotted watching her mum and dad from a sound area in the middle of the venue, despite being way past her bedtime!

MORE: Is this the most beautiful dress Princess Eugenie has ever worn? 

Last weekend, Eugenie made headlines after the annual Trooping the Colour ceremony when she went against usual royal protocol by sharing a picture from inside Buckingham Palace, to pay tribute to her dad, Prince Andrew. Showing her obvious pride in her father, the royal shared a photograph of her father in his impressive military finery.

"A wonderful and proud day celebrating Her Majesty's birthday and @hrhthedukeofyork for his first Trooping the Colour as Colonel in Chief of the Grenadier Guards. #troopingthecolour, " she wrote alongside a picture of the Queen's son posing inside the palace, looking happy and smart in his Grenadier Guards uniform.