Jesper is tough to best, and you'll most likely need some tips. Here are some tips to help defeat the mighty Swedish powerhouse.
~Jesper uses alot of power, so theres no use in challenging him in a topspin power battle, try to only use left, right, and backspin
~Try and use right spin alot to the right of the table, it will pin it into Jespers backhand, forcing him to move to the extreme left, giving you an oppurtunity to shoot to the left, and have it out of his reach
~Jesper also will be tempted by a backspin shot into the far side of the table, he will (sometimes) hit it off the table when given such a perfect shot oppurtunity
~When serving the first time, it helps to move over to the left as far as you can, and put max rightspin on it and max power, to the right side of the table. He should miss it.
~If you do engage in a topspin battle, wait until he's at the far end of the arena and then do a soft shot just over the net.