At his audition, Monga performed a version of "Hit the Road Jack" using a loop pedal. He received a standing ovation from all four judges and positive comments. As of 2022, his audition has received over 85 million combined views on Facebook and YouTube after going viral online. After the elimination of Nofo Lameko on week 2 and Stevie Tonks in week 9, Beau was the final act on the boys category who progressed through to the grand final. Going into the grand final, Beau was also the only act in series 2 who never landed in the bottom two. He eventually won the series after beating Nyssa Collins and Brendon Thomas and The Vibes in the grand final. He was initially mentored by Natalia Kills, but he was replaced by former Australian judge Natalie Bassingthwaighte after Kills was removed from the show due to a bullying controversy in the first live show. He is the first male winner of The X Factor NZ.