The fighter is a kind of martial controller if you select the correct powers, but it doesn't start before level 7 with the encounter power Come and get it, which pulls all enemies in burst 3 adjacent to you, then let you hit them. Then you can follow up with the level 3 encounter power Sweeping blow which lets you hit everybody in close burst 1, and then you can follow up with a level 1 encounter power, passing attack that lets you hit two targets. A level 5 daily power, Rain of steel makes all the enemies that are adjacent to you take damage. At level 9 you have two powerful close burst 1 attacks, Shift the battlefield and Thicket of blades.
It all depends on Come and get it, the level 7 encounter power that pulls the creatures adjacent to you. Without it you are probably hitting 1-2 creatures, with it you are probably hitting 3+ creatures at once. It has some great synergy with the cleric powers that attacks enemies in burst/blast since.
The best part of all this, is that the fighter will be fulfilling his role as a defender in addition to the controller-ish stuff (hitting multiple foes at once).