Some 7.4 million "Glee" fans watched the Thursday night episode of the musical show, dedicated to the 31-year-old who died of an accidental drug overdose in July, according to Nielsen ratings cited by Variety.
The Twittersphere inevitably went mad before, during and after the third episode of the series's fifth season, in which fellow glee club members sob in front of a makeshift shrine in front of his character Finn Hudson's old locker.
But critics were divided over how well the episode handled the emotions.
People magazine called the show "beautiful," and hailed the "dignified" decision not to specify how the character had died.
The episode was "an hour that was very moving -- how could it not be? -- but also very kind," it said.
The Hollywood Reporter called it "a respectful memorial and cathartic hour for the cast and viewers alike."
But it said: "Though the show chose to not reveal the cause of Finn's death, viewers all knew the cause of Monteith's, and to bypass that teachable moment seemed not only like a missed opportunity, but nearly irresponsible."
Entertainment Weekly called it an "earnest, flawed tribute to the life (not the death) of Cory Monteith."
"One of the challenges facing the producers and actors was managing the reality blur of Monteith and Finn, the characters' grief and their own, and this was one moment where they got it wrong," it wrote.
And Variety added: "The sendoff is emotional and heartfelt, but also feels like a missed opportunity."
Monteith had starred in the Fox TV musical comedy-drama since it debuted in 2009. His character, Hudson, was a star high school football player who joined a motley crew of students in the glee club.
The actor, who had struggled in the past with substance abuse and checked into a rehab facility in April, was found dead July 13 in his Vancouver hotel room in western Canada.
