The former Doctor Who actor was co-hosting the Christian O’Connell Breakfast Show on Absolute Radio on Friday.
But after taking over all of presenter Maggie Doyle’s travel bulletins she decided to get her own back and slap the actor in the face with a fish.
She had the choice between a rainbow trout, see bass and a smoked haddock to which she commented “they all stink”.
After kitting out Tennant with a poncho, sombrero and a pair of goggles because he “would stink all day” the Irish presenter chose the rainbow trout as her weapon.
She said: “I need a little tissue. It’s quite slimy. “All morning for all my travel bulletins I’ve been pushed aside.”
To which Tennant replied: “We went tag team on the last one Maggie just remember.” But she added, “Yeah well too late, too little too late” before slapping him in the face with the trout.
The radio team roared with laughter as Maggie said: “There was a bit of fish slime that fell of the side of his face.”
And the antics have all been videoed and placed online so that the actor cannot hide from the embarrassment.
The radio show has Fish Face Friday every week in which a variety of guests are slapped in the face by a fish.
This is the fifth time that Tennant has appeared on the radio show.