In most situations, you would fight the fish from the front of the kayak. However, if the fish you are fighting starts to drag your kayak into dangerous waters – say a structure or some reeds – turn your body 90 degrees so that you end up fighting it from the side of the kayak instead. This will greatly increase the amount of water resistance and slow down your kayak’s forward movement.
Another more obvious method, if you have a drive system in your kayak, would be to simply pedal backwards. While this is more tiring, it is a sure-fire method that allows you to reverse any amount of ground that you may have already lost in the process of the fight.