Sheikh Hamdan's son of Kyllachy has improved with each start to date and put his experience to good use when winning well under Jack Mitchell.
Jack was always to the fore on the 8/1 chance, alongside the leader Mobsta. The pair began to draw clear with two furlongs to run and Jack made his challenge at the furlong pole.
Mujassam struck the front with 100yards to run and was pushed out to win by half a length.
Roger said: "Experience often counts when it comes to soft ground maidens and Mujassam has put his past experiences to good use.
"The six and a half furlong trip has suited him and he has handled the ground well. He will stay further next year."