“30 Rock” (8:30 p.m., NBC): Jerry Seinfeld ruled the ratings on Thursday night for

“30 Rock” (8:30 p.m., NBC): Jerry Seinfeld ruled the ratings on Thursday night for years, but can he help inject some Nielsen firepower into “30 Rock”? He has a guest appearance on the show, which returns for its second season fresh after a stunning victory as Outstanding Comedy at the Emmys.

“Last One Standing” (9 p.m., Discovery Channel): Three athletes from Britain and three from the United States immerse themselves in the rituals of remote tribes in this competition series. The men train to take part in contests of endurance and skill, such as stick fighting, canoe racing, wrestling and tribal cricket, all in far-flung regions, including Brazil, South Africa, Mexico and New Guinea. The 12-part series follows the men, individuals who are accomplished in sports and fitness, as they cope with challenges that test their physical and mental limits. One man will be designated the winner based on his successful completion of the events.

“Law & Order: Criminal Intent” (10 p.m., USA): If you’ve been looking for “Law & Order: Criminal Intent” on NBC, you won’t find it there. The crime series has been shifted to basic cable, where it begins its seventh season tonight. Alicia Witt (“Cybill”) joins the show as a temporary replacement for Julianne Nicholson, who is on maternity leave.