Univision outperformed The WB and UPN in total viewers and 18- to 49-year-old viewers in prime time during the first few days in which the Spanish-language broadcaster was included in Nielsen Media Research’s national ratings sample.

When the preliminary nationals for last Tuesday and Wednesday nights arrived, Univision, which fielded no repeats on those two nights, outperformed The WB and UPN, neither of which offered original episodes of their regular series. Univision also appeared to be up dramatically from the same lineups the previous week, which included Christmas.

It will take more time and data to know whether Univision’s drawing power during what is one of the least-watched weeks of TV shakes up the rankings on a long-term basis.

Following several days characterized by longer-than-expected delays in crunching final ratings data, by last Thursday morning Nielsen Media Research executives told their clients they could see the light at the end of a clogged data tunnel.

Nielsen experienced numerous delays in reporting viewership figures last week while grappling with three major hurdles: the inclusion of Univision in its reports for the first time, the addition of DVR information and the holidays.

Nielsen sent out revised delivery schedules for the final national data for each night last week, which were to have been delivered the following afternoons. Nielsen expected to deliver Monday finals (including time-shifting viewing data and Univision) last Thursday morning, Tuesday finals Thursday afternoon, Wednesday finals Friday morning and Thursday finals Friday afternoon.

No new insights into DVR usage emerged from Nielsen’s first few days’ worth of DVR data, which included live and time-shifted same-night viewing information from DVR homes in its National Television Index.

Still to come, in the week of Jan. 30, is the addition of Telemundo to the national sample. A Nielsen spokeswoman said the company does not expect a repeat of last week’s glitches.

Nielsen’s production team now has “got the answer and they’ve got it solved going forward,” she said.