The BBC says it will ensure an on-screen ad during the climactic seconds of Saturday's Doctor Who will not happen again, after it prompted thousands of complaints.
The corporation conceded the "banner" - featuring an image of Graham Norton - which popped up during the show - should not have been screened.
Around 5,600 viewers complained about the image which they say spoiled the drama as the latest Time Lord adventure reached its peak.
The banner was plugging the edition of Over The Rainbow which followed the hit show, starring Matt Smith as The Doctor. It appeared just seconds before a cliff-hanger ending as The Doctor's pals were being pursued by the spooky weeping angels.
The BBC said: "The Over the Rainbow trail in Doctor Who should not have played out on Saturday and we apologise to all Doctor Who fans whose enjoyment of the show was disrupted.
"We recognise the strength of feeling that has been expressed and are taking steps to ensure that this mistake will not happen again."