Does shouting 'stop' ever work?
"Spear!" With that dubiously magic word the wizard thrusts one hand into the air, ripples flowing through the fabric of existence around him and stealing an atom here, an atom there, with which to conjure forth a spear forged of purest silver into the outstretched hand.
Said spear is promptly jabbed stabby-end first towards the charging elemental, set to run it through by it's own momentum should it not change course.