WATCH: Bruce Springsteen was joined on stage by a very special guest in Croke Park

Two icons sharing centre stage.

While many people were unhappy with the sound quality at the Bruce Springsteen gig in Croke Park this Sunday, the majority of fans were in heaven. And that was all before they got a very special surprise in the shape of an all-time music icon; Bono. Twitter was alive and loving every minute... https://twitter.com/Salwicklow/status/737016863297798145 https://twitter.com/Clairemsings/status/737017941368115200 https://twitter.com/U2History/status/736994426258657282 https://twitter.com/fdomenella/status/737015311564742656 https://twitter.com/LynetteFay/status/737015852772536320 https://twitter.com/GreasyLake/status/737016367640117248 https://twitter.com/IllSueYa/status/737016560431333377 https://twitter.com/ncooney6920/status/737016670426923008 https://twitter.com/LanaRedFM/status/737016860374360064 https://twitter.com/ciara_cotter/status/737018148839362561 https://twitter.com/stefantasist/status/737017981788655616 https://twitter.com/Marcus29MM/status/737020246847033344 https://twitter.com/fionam30/status/737020470772531201 https://twitter.com/TedLeddy/status/737023041197199364