The former tour presenter told The Mirror that the boys stood out despite the impressive singing of winner Matt Cardle and runner-up Rebecca Ferguson.
Brazier said: "The outstanding vocal performances were from Matt and Rebecca (obviously).
"The overall biggest shock of the night was how hard One Direction have clearly worked since the show because they were fantastic! They got the most love from the crowd and deserved every swoon."
He added: "It was lovely to hear that Katie Waissel is genuinely a lovely person with a great attitude, that the Matt and Aiden [Grimshaw] bromance is still in full swing, the 1D boys remain as grounded as when I interviewed them for This Morning before X Factor kicked off and that the lovely Rebecca manages to keep up with her children by having them down to the tour every weekend."
It has been claimed that Ferguson is dating One Direction star Zayn Malik, while Cardle is reported to have started a relationship with backing dancer Sarah Robinson.