For the second consecutive night, Piers Morgan allowed his high-profile guest — first Oprah Winfrey, now Howard Stern — to essentially hijack his program.

Piersmorgan Morgan was less obsequious with Stern than he was with Winfrey, but his efforts to press him on whether he felt responsibility for exalting porn stars and probing into stars’ personal lives on his program never really went anywhere. Stern ran rings around him, making Morgan uncomfortable by bad-mouthing his predecessor, Larry King, as well as CNN management.

Although the mix of newsmakers — celebrities and political figures, including Condoleezza Rice on Wednesday — is similar to King’s formula, thus far Morgan has more in common with fellow Brit Robin Leach, who hosted “Lifestyles of the Rich and Famous.” CNN is celebrating the big tune-in the show got with Winfrey on Monday, but one suspects this week of false positives will drop quickly — as Stern wryly suggested — unless the show becomes hipper and quicker once the front-loaded A-list fades and Morgan is interviewing Scott Baio.

The bottom line is that there aren’t many interview subjects, in today’s day and age, that an audience will patiently sit and watch for a full hour unless the host brings something fresh and unique to the conversation. So far, Morgan isn’t delivering those goods.

Stern did his best to keep things interesting, trashing Jay Leno as a no-talent hack and saying that Americans must be “morons” for his show to attract a larger audience than David Letterman, for whom Stern expressed great admiration.

Morgan tried to counter Stern’s bravado with some of his own, but Stern’s closing warning about CNN management’s itchy trigger finger could prove prescient once “PMT” finishes its opening-weeks tour of America’s media royalty. Just ask the folks at “Parker Spitzer.”