Performing the first of four sold-out nights in the 3Arena last night, Niall Horan was shocked to see one person in the crowd.

The former One Direction member took to the stage in front of 13,000 fans at the 3Arena last night, performing songs from his extensive discography.

Niall Horan was clearly feeling sentimental, telling the crowd: ‘The number of times that I’ve gotten goosebumps so far in this show, I can’t believe the turnout for me this week; it’s just ridiculous.’

However, Niall was left shocked at one point during the show after noticing a familiar face in the crowd.

Among the wave of adoring fans, the singer noticed his third-class teacher enjoying his music in the 3Arena.

‘Oh my God, I’ve just spotted my third-class teacher, Mrs Anne Caufield,’ he told the crowd as she smiled back up at him.

The singer continued: ‘Anne is the reason I started singing … She gave me my first solo part in Away in a Manger, when I was about five or six years old.

‘She then gave me the part of Oliver in the play Oliver Twist. To be fair there was a bit of bias because I was in your class. You could have picked your son to be fair.

‘She really is the reason I started doing all of this, give it up for Anne, come on.’ The crowd then erupted in applause for the teacher.

A concertgoer has since posted the clip to social media, with fans of Niall Horan noting how cute the moment was.

One concertgoer noted: ‘I was sitting behind her! She was smiling from ear to ear!’

Niall Horan was playing the second night of his sold-out stint at the 3Arena when he spotted the teacher. He will play two more nights on Thursday and Friday before taking to The O2 in Belfast on November 15 and 16.