* Some 3.2 million Americans watch Armstrong's TV confession
* Steely Oprah Winfrey gets high marks for effort
* OWN hopes interview will translate into more regular viewers
By Jill Serjeant
LOS ANGELES, Jan 18 (Reuters) - Oprah Winfrey's exclusive TV interview with disgraced cyclist Lance Armstrong drew 3.2 million American viewers - less than the record number who watched the talk show queen interview the family of singer Whitney Houston a month after her death.
Ratings figures on Friday from Winfrey's struggling cable channel OWN showed the 90-minute interview with Armstrong, in which the cyclist admitted taking performance-enhancing drugs for years, was the second-most-watched telecast in OWN's short history.
Winfrey, 58, regarded as the most influential woman on U.S. television, won high marks from media critics for her effort to get the truth out of Armstrong, and showed off a steely side audiences have rarely seen.
But the much-anticipated encounter on Thursday failed to top the 3.5 million people who watched Winfrey interview the teenage daughter of "I Will Always Love You" singer Houston in March last year.
The Lance Armstrong audience rose to 4.3 million after a repeat showing on Thursday, and drew the biggest male audience to OWN's female-oriented lifestyle channel, OWN said.
In addition, nearly 600,000 people watched an online stream of the interview on Oprah.com, an OWN spokeswoman said.
Winfrey quit her daytime TV show in 2011 to launch the Oprah Winfrey Network, a joint venture with Discovery Communications .
The Armstrong interview generated a wave of publicity for OWN and high demand for advertising that executives hope will translate into more regular viewers.
A second, hour-long portion of the interview with air on Friday evening.
Critics largely praised Winfrey for doing her homework and digging away at Armstrong's sometimes evasive replies.
"This is one sick dude, and Winfrey was surgical in peeling back the flesh and adjusting the lens so that we could clearly see the pathology that's eaten away at the place where Armstrong might have once had a conscience or some sense of right and wrong," wrote David Zurawik of The Baltimore Sun.
Mary McNamara at the Los Angeles Times was gushing. "One interview, 75 different ways to cover it. Honestly, even after all these years, the woman's media moxie just takes your breath away.
"With this interview, she is offering, perhaps, a twist on her persona, an ability to work with a harder edge, to take on people and issues some feel should be left to journalists," McNamara said.
The New York Times' Alessandra Stanley was less effusive, saying Winfrey "did her best to get answers, but she didn't get all of them, and she didn't pierce his armor."
Entertainment Weekly's Ken Tucker said that while Winfrey "conducted a sharp, precise interview, she could not help but feed whatever demons still reside within Lance Armstrong."
CNN's Howard Kurtz, under the headline "A Loss for Lance, a win for Oprah," said Armstrong had "utterly failed" to win public sympathy.
"Winfrey's challenge was to reclaim a bit of the cultural spotlight that she once owned before abandoning her syndicated stardom for the cable netherworld. She clearly succeeded," Kurtz wrote.