The Pop Idol star went to number one last week with his self-penned debut song, Colourblind.
Gareth's second single, Anyone Of Us (Stupid Mistake) dropped to number four.
But Madhouse got a new entry at number three with their dance cover of Madonna's Like A Prayer.
Bowling for Soup also got a new entry in the top 10 with their rock tune, Girl All The Bad Guys Want.
In the album charts, the Red Hot Chili Peppers are back at the top spot with By The Way.