beggining of Shippuden, this is because Sasuke gained a lot of experience, knowledge and power while working under Oro, whereas kakashi seemed to do no training whatsover until late into the Shippuden series.
- this can be seen when Sasuke is able to use "True Chodori Blade" and Kakashi is still yet to master his "lightning beast running Technique" (or atleast we didnt see it until the Pein arc (i beleive)) - both of which are extremely similar techniques. Also the use of Oro's curse mark (which hasnt been seen since Sasuke got MS >.<) means he naturally outweighs kakashi's power.
On the other hand - Kakashi can use four elements - lightning affinity, water, earth and (anime only) - fire - where as sasuke can still only use two - fire and lightning. so Kakashi's fundamental knowledge and skills are probably better than Sasuke's.
Kakashi has MS aswell - but only in one eye...and instead of using tsukuyomi & amaretsu he uses kamui (although it uses a lot more chakra then it does for Sasuke)