Conor McGregor beat Dennis Siver with a second-round knockout in their UFC bout in Boston shortly after 5am this morning.

After the bout the Dubliner confronted world featherwight champion Jose Aldo in the crowd and the two were held apart by security.

A hoped-for world title shot in Croke Park this summer is now an outside possibility, but in all likelihood the 26-year-old Dubliner will have to go to Las Vegas in order to dethrone Aldo, following UFC president Dana White's comments yesterday.

White says they are looking at May in Vegas for Aldo vs McGregor.

— Ariel Helwani (@arielhelwani) January 19, 2015

Tallaght man Paddy Holohan got the Irish contingent off to a perfect start at UFC Boston with a unanimous victory over Shane Howell, while Norman Parke lost his unbeaten record against Gleison Tibau, with the Antrim man going down to the Brazilian on a split decision, 29-28, 28-29, 29-28.

There was controversy in Cathal Pendred's fight. The Boston-born Irishman took his third UFC triumph against Sean Spencer on the preliminary card, the judges awarding his a unanimous decision - 30-27, 29-28, 30-27.

However UFC commentator Joe Rogan reckoned Spencer had been "robbed" - and said so on the live broadcast. It was a view Dana White concurred with later.

Thanks for the most amazing birthday of my life @PaddyHolohanMMA @PendredMMA and @TheNotoriousMMA pic.twitter.com/lvjKiTOCYb

— Coach Kavanagh (@John_Kavanagh) January 19, 2015