The last-ever episode of sitcom Frasier attracted 25 million viewers when it was broadcast in the US on Thursday.
Grammer has played the character for a total of 20 years on NBC
The hour-long episode brought the curtain down on 11 years of television and 264 episodes.
The sitcom, based on the life of psychiatrist Frasier Crane, won a record 31 Emmy Awards since it began as a spin-off of TV comedy Cheers.
Frasier only managed to draw half the audience that had watched Friends bid farewell, a week earlier.
It went on to match Cheers' 11-season run, with only Dallas series Knots Landing having longer spin-off success.
Created by Cheers writers David Angell, Peter Casey and David Lee, the sitcom poked fun at the highbrow neuroses of Frasier Crane, played by Kelsey Grammer, and his brother Niles, played by David Hyde Pierce.
Frasier ended in the US with a two-hour finale, including an hour-long retrospective.
It was not expected to draw the 80.4 million US viewers who tuned in for the last episode of Cheers in 1993, making it the second most-watched TV series finale after MASH.
Nor was it expected to attract the 51.1 million who watched last week's finale of Friends. Nevertheless those who are part of Frasier said it would go out in style.
The 25.4 million viewers who saw the finale made it the most watched episode of Frasier since October 2000
A date has not been set for the UK broadcast of the final episode of Frasier, but a Channel 4 spokesman said it would be shown at the end of June.
Grammer, whose Frasier character was introduced on Cheers in 1984, has equalled the record for the longest-running role portrayed by a single actor in prime time, first set in 1975 by James Arness as Matt Dillon on the western Gunsmoke.