Lets see... saber skills, Ani is a 7, Maul's a 7 or 8 (more likely an 8). Anakin only lasted 50 seconds against Dooku, Maul took on both Obi-Wan and Qui-Gon at the same time and nearly won. He took out Qui-Gon, who is a very pwoerful Jedi Master and could beat Anakin. In the EU he took out Anoon Bondara, who was described as the most skileld Jedi with a lightsaber in the Order at the time when Maul killed her, infiltrated Black Sun all at once and pwnd them all, and even withstood Force Lightning. I have total confidence that he could pwn Anakin and can tlel you right now that every one here will agree that he beats Anakin.
Maul beat the crap out of Qui-Gon and Obi-Wan. When Qui-Gon revitalized himself, Maul beat in a minute. When ferocious Obi-Wan (who's greater than AotC Anakin) attacked Maul (who's at a disadvantage due to Obi-Wan's sudden charge) but still Maul was able to knock him down and throw his saber away. Darth Maul will comfortably defeat Anakin.
Maul > AotC Anakin
End.of.Thread
Maul was not at much of a disadvantage because of a furious attack. He's definately sparred against Sidious, so he would be used to random attacks. Anyway, he would have had the advantage of a dual sided lightsaber, but he may have been hindered in the confines of the energy room, much like how Qui-Gon's Ataru was restricted.