The sass-off is a rite of passage for any Doctor meeting their younger self That time in The Day of the Doctor when the Eleventh Doctor (Matt Smith) met the Tenth Doctor (David Tennant). Every Doctor, every companion, every enemy. Discover the Whoniverse. Only on iPlayer. #DoctorWho #DavidTennant #MattSmith The Day of the Doctor: The Doctors embark on their greatest adventure in this anniversary special. All of reality is at stake as the Doctor's dangerous past comes back to haunt him. | BBC