But I've never had a chance to answer that question so I'll do so anyway <smile>. I typically get to that point with 2 warriors about the same level.
The keys to making that fight rather easy are IMO:
1. Whatever weapon you are using have it sharpened to the maximum (subject to your agility). This makes a ridiculously big difference. Cash isn't that hard to get - if you must, forget another skill, learn sharpen, use it, then forget it and relearn the other skill.
2. If you have a decent 2H weapon use it and switch your skill as needed. If you are 1H and don't feel like a switch, make SURE that if you have a shield your skill is in 1H + shield and if you don't your skill is in pure 1H. otherwise the skill is wasted. Put skill points mostly in accuracy and critical/deathblow.
3. Fight smartly. Have the character with the better armor class take the attacks (if there is a difference between your two). Remember that you can pause an unlimited number of times and suck down enough potions to drown an elephant. Use the spacebar/potion routine as needed and the fight should be easy. I haven't needed to take a potion to kill a deathknight at your level for a number of games - since I figured out how to optimize (more or less) a warrior but if you need potions take them.