The final four sing in The X Factor semi-final

The last four contestants on The X Factor fought it out tonight for a place in the final.

It was an emotional night as each of the acts performed two dedications - each one with a personal meaning.

The last boy band standing Union J, joint-favourites James Arthur and Jahmene Douglas and over-28 contestant Christopher Maloney now have to wait until tomorrow night to see if they have made it through to the grand finale in Manchester.

Gary Barlow's contestant Chris Maloney received a good comment from Tulisa
Gary Barlow's contestant Chris Maloney received a good comment from Tulisa Credit: Twitter/@thexfactor

Maloney - who has been regularly booed throughout the past few week's of the talent show - dedicated Josh Groban's You Raise Me Up to his nan.

He told her, "You made me go to the first audition, you're my Number One fan".

Arthur plumped for a take on U2's anthemic One, dedicated to his siblings.

Gary Barlow described James Arthur's song as 'the performance of the series'
Gary Barlow described James Arthur's song as 'the performance of the series' Credit: Twitter/@thexfactor

Gary Barlow described the singer as "a musical boxer", saying, "You come out ready for attack each week, knocking the opponents down one by one," while Louis Walsh said he thought the singer would have "three or four albums" by this time next year.

Union J, who plumped for Labrinth's Underneath Your Beautiful, said the performance was for their fans.

While Barlow praised the band for "blending brilliantly", fellow judge Nicole Scherzinger added, "You are cheese-free".

Jahmene Douglas wows The X Factor crowd
Jahmene Douglas wows The X Factor crowd ahead of tomorrow's results Credit: Twitter/@thexfactor

But it was Douglas who drew tears from the judges, as he dedicated Whitney Houston's I Look To You to his late brother.

Douglas' mentor, Scherzinger, wept as he finished the ballad, saying, "I surrender. I could sit here and say you're vocally the strongest and most dynamic singer but that's not what it's about".

There was a lighter mood for the second half of the show. Douglas, in a reprise of his first audition for the competition, sang Etta James' At Last, while Union J tackled Lonestar's I'm Already There.

Boy band Union J had a mixed night
Boy band Union J had a mixed night on semi-final evening Credit: Twitter/@thexfactor

Arthur performed his take on Frankie Goes To Hollywood's The Power Of Love, which Barlow called the "performance of the series".

Maloney opted for Michael Buble's I Just Haven't Met You Yet. But Walsh described it as going "back to the karaoke thing".

The four judges have been stripped of their voting powers for the semi-finals, meaning tomorrow's result is entirely decided by The X Factor viewers.