Or Draconic Reservoir for Greater Rite of Passage for a 1st level spell 3/d and 1st level Sorcerer casting.
Oh man, my PCs had a time with that one. I ran an eighth level party through a Kobold warren filled with almost nothing but level 1 Kobolds (the boss was level 3). The Kobold Rogues were especially hilarious with Grease. I heartily advocate this.
What does the party look like, in this case? Turn Resistance is thematic, but useless if there isn't a Cleric to worry about. Though if there is, it might not be enough. Turn Undead doesn't get used for turning undead much these days, but it's really good at it.
Vampire is a melee monster in this case, so he needs a way to close the gap with the party. Going first (improved initiative and charging), teleporting in (travel devotion or a level 1 mobility spell with Draconic Rite of Passage), and sneaking are all good options. Only consider Darkstalker if your players actually have touchsight/blindsight/tremorsense/etc.
Then he needs to be able to disable part of the party immediately. One-on-Three+ is bad odds, ya know? This is where Greater Rite of Passage will give you a serious option that most straight-up melee monsters don't have. Grease continues to be a favorite, with the added sweetness of usually being a PC tactic.
Now he just needs to wail on someone with energy-drain. I assume your party is somewhere in the 4 to 6 range. I actually advocate isolating an arcane spellcaster by disabling everyone else - melee dudes probably don't have the DEX to recover from grease quickly, and Divines like to wear heavy armor (Clerics) or dump DEX because lolwildshape (Druid). The benefit of being undead is immunity to many low-level save-or-lose spells, so the Vampire should have a round or three to slam the spellcaster. By that time, the greased party should have time to recover and get themselves in sorts. A credible threat that looks like a close call, but is survivable.
Tacking Precocious Apprentice onto Draconic Reservoir (if that works) can open some hilarious stuff. Glitterdust, ghoul touch, touch of idiocy...