NBC’s “Today” ranked first in the morning race Jan. 31-Feb. 4 for Nielsen daytime and fringe ratings, while the latenight race continued to heat up with increased viewing of both “Late Show With David Letterman” and “The Tonight Show With Jay Leno.”“Today” (a 4.8 rating/20 share) ended a 21-week losing streak a week earlier and has now edged “Good Morning America” (4.7/19) two consecutive weeks. The NBC show also enjoys a comfortable lead among adults 18-49, with a 2.1 rating to “GMA’s” 1.7 and a 1.3 for the now-competitive “CBS This Morning,” which posted a 3.5/14 in households and continues to perform relatively well despite its perennial third-place status. Letterman, Leno up Letterman rebounded from a repeat week (when his show trailed “Nightline”) to easily win latenight with a 5.9/18, even though “Tonight” (4.8/15) had its best rating since the week of Dec. 20 and best share since June, prior to “Late Show’s” premiere. From 11:30 to midnight, averages were “Late Show” 6.7/18; “Tonight” 5.7/15; and “Nightline” 5.6/15, a rare third-place finish for the ABC newsmagazine, which is nonetheless up 8% compared to the comparable six-week stretch a year ago. “Tonight’s” improved position helped “Late Night With Conan O’Brien” (2.0/10) score its best numbers since its September premiere — a timely performance considering fears that affiliates will downgrade the series. The Feb. 4 episode had the highest rating since the show’s opening night. The CBS daytime win streak has grown to 257 weeks, or three short of five full years as the No. 1 network. The Eye web averaged a 6.5/23, compared to ABC’s 4.7/17 and NBC’s 3.0/11. Averages among women age 18-49 were CBS, 3.9; ABC , 3.7; NBC, 2.3. NBC continues to struggle with its new talkshows, “Jane Whitney” and “Leeza,” which are also suffering from a clearance handicap. The Fox Children’s Network had another huge week in the Saturday-morning race , averaging a record 8.1 rating among kids 2-11 and 3.7/13 in households. FCN scored solid numbers withits premiere of “Where on Earth Is Carmen Sandiego?,” which tracked down an 8.1/33 among kids following “X-Men.” For the same four hours, ABC and CBS tied with a 4.5 rating each among kids, with a 2.5/9 and 2.9/10, respectively, in households.