Arrival of thick crustal material (continental/oceanic terranes) to subduction zones can cease subduction by choking the subduction channel. This is usually followed by partial or full accretion of these allochthonous fragments to the overriding plate. When subduction stops, dense ocean slabs still tend to sink and exert tensional stress to the buoyant terranes (or continents) and eventually detach from them yielding slab tear or a complete slab break-off. If the subduction system has an oceanic overriding plate (intra-oceanic), this collision and break-off succession can also trigger a subduction polarity reversal. Although slab break-off and subsequent subduction polarity flip have been suggested to explain many geologic problems, the mechanism and timing of the tectonic event are not well constrained.Here we provide numerical experiments that show slab pull can stretch the incoming edge of the terrane lithosphere and facilitate such fast break-off events. In our models, break-off usually occurs in the stretched portion of the terranes or at the terrane-subducting plate transition, contrary to ocean slab break-off. Furthermore, we supplement our numerical experiments with an extensive compilation of geological, petrological, and geophysical evidence and provide a temporal range for slab break-off and subduction polarity reversal following a collision event. This compilation highlights the timing to be very short (~2-5 Myr) and in agreement with our model results. Evidence for these fast events can be found in several contemporary and ancient subduction systems and associated orogens such as Central Apennines, Ontong Java Plateau, Eastern Carpathians, New Zealand, and Bohemian Massif.