Break the Flow
Description: The mage can disturb the flow of quintessence which sustains a magickal effect. This is done by disturbing it so it won't discharge into its target, but into something else or just into reality in general. This will disrupt the magick for a short while (some types of magick may even be dispelled by this). This of course only works on magick which is fueled by a flow of quintessence or is upheld by a concentrating mage. It will temporarily break down a barrier,make an eternal flame go out or turn a temporarily boosted Life-mage normal. Hermetic mages usually perform this by "cutting off" the power with their seal, while intoning the name of a powerful god or force.
System: Each success removes one success from the affected magickal effect. If it is of the type which demands constant influx of quintessence to function and remain in existence, like a flame or ward, it may be completely dispelled if all successes are removed. Matter and Life magick will return to normal function as power returns.
Source: SCRIBD (Apprentice Rotes for Mage: The Ascension), Uploaded by Beth on Jun 19, 2008, originally part of "The Grimoire of the Cabal of Pure Thought", a resource for my Mage: The Ascension game. None Commercial.