Saara previously announced her own headlining show in her native Finland, following the X Factor live tour which concluded last month
"My first own arena concert ever!! At Hartwall Arena, Helsinki, on 15.4!" Saara told fans last month. "In My Wildest Dreams, definitely.. I never saw this coming so fast!!"
She said: "This is a thank you concert for all of you who supported me throughout the autumn! This is gonna be the best night! <3 "
Saara later revealed that Matt, who beat her to the win in last year's final, would be joining her at the show.
“After the X Factor tour I’m going to have my own arena concert in Helsinki,” she said on Good Morning Britain. “It’s going to be great.
"13,000 people are coming and I really wanted to bring a part of X Factor with me to Finland, so Matt is coming to Finland to sing with me on my arena concert, which is really great.”
Matt himself added: “We met the first time on the coach at Bootcamp. She was the first person I spoke to, I was carrying her suitcases.
“To think we’d both be in the final together and now we’re going to Helsinki together.”
The pair shared the stage tonight in front of a crowd of thousands, with Saara singing songs including The Winner Takes It All and Everybody Wants To Rule The World.
"WHAT A NIGHT !! @saaraaalto thank you for having me 🙏🏼You were outstanding !!! I love you 🙌🏼🙌🏼 See you soon Finland you were awesome! 🇫🇮" Matt, who duetted with Saara on You Had My Heart, said.