The Explosion

The Explosion was a type of regeneration in which a Time Lord was consumed by "a dramatic and instant burst" of fiery golden regeneration energy. Subtypes of the Explosion included the Slow Explosion and the Reverse Explosion. (PROSE: How to be a Time Lord)

By one accounts, the Doctor started regenerating in this manner due to the regeneration cycle granted by the Restoration. (PROSE: Doctor Who and the Time War) Rose Tyler, after witnessing the Ninth Doctor regenerate into the Tenth Doctor, (TV: The Parting of the Ways) likened the process to an explosion. (TV: Born Again)

During the Planetary Relocation Incident, the Tenth Doctor was forced to regenerate when he was shot by a Dalek. Though the process began much like the last time, (TV: The Stolen Earth) the Doctor, after using the regeneration energy to heal himself, siphoned the rest into his severed hand, thus preventing himself from changing. (TV: Journey's End)