Implosion

When two versions of the Doctor's TARDIS collided, the Tenth Doctor, after witnessing himself doing so in his fifth incarnation, combined a black hole and a supernova to stop a black hole from being created, observing that the explosion canceled out the implosion. (TV: Time Crash)

Behind the scenes

 * In NOTVALID: The Curse of Fatal Death, a damaged Zectronic Beam Controller threatens to both explode and implode before being fixed by the Twelfth Doctor.