The band, consisting of Emma Bunton, 43, Geri Horner, 46, Mel B, 43, and Mel C, 45, delighted the crowd of around 58,000 fans with a medley of their greatest hits, and Geri even paid homage to her iconic Union Jack dress with a red and blue renaissance-style gown.
While many fans took to Twitter to share their excitement about attending the concert, others were quick to share their disappointment as sound problems inside the stadium meant they were unable to hear the show, and one fan even claimed they saw "huge numbers" walking out of the show, reports dailymail.co.uk.
Several also bemoaned the issues given how much they had spent on the sold-out concert, with ticket prices ranging from 66 pounds to 146 pounds.
At one point Mel B left the crowd staggered as she screamed "we're having a f****g great time", as she and the group chatted to the elated crowd, reports dailymail.co.uk.
She continued by shouting "cut the c**p", before making a bizarre comment about racism as she claimed she was "allowed to be (racist)", she said "Everyone knows I'm racist, I'm allowed to be I'm black."
The singer took to the stage alongside her bandmates in Dublin as they kicked off their nationwide reunion tour in fierce style following a recent eye infection.
Mel B shocked fans by swearing during the action-packed show before twerking against a backing dancer wearing her iconic leopard-print catsuit.
The tour commenced without former bandmate Victoria Beckham.