Both Ashton Kutcher and Charlie Sheen have something to brag about after their big nights on television, Sapa reported.
The sitcom's previous best came in May 2005 following the final episode ofEverybody Loves Raymond.
Meanwhile, Sheen appeared Monday as the "victim" of a Comedy Central roast that reached 6.4 million people.
That is the second most-watched telecast in the cable network's history, behind only Jeff Dunham's holiday special in 2008.
The season-opening episode of Two and a Half Men, television's most popular comedy, was much anticipated. Producers kept it a secret how they would kill off Sheen's character and introduce Kutcher's.