SECOND UPDATE PM: With the final Nielsen numbers in, the NFL kickoff game between the Saints and the Vikings averaged 27.5 million viewers to become the most-watched regular season primetime NFL game in 14 years.

UPDATED: Last night’s NFL season opener between Super Bowl champions New Orleans Saints and the Minnesota Vikings drew a 17.7 overnight rating/28 share – the best for any NFL regular season primetime game in 13 years and the best ever for an NFL kickoff game. The faceoff, a rematch of last year’s NFC Championship Game, was won by the Saints 14-9. It gave a very strong start to the season for the NFL, which faces the possibility of a lockout next year. NBC dominated primetime with a 15.9/26 average in the metered markets, beating the combined delivery of CBS, ABC, Fox and CW. The premiere of the CW’s new Thursday lineup was no doubt affected by the hugely-rated game, though it’s worth mentioning that last year the network also premiered its Thursday dramas The Vampire Diaries and Supernatural against the NFL kickoff game. The season 2 opener of Diaries drew 3.4 million viewers, down 30% from last year’s big debut. In CW’s target demo 18-34 (1.9/6), the decline was smaller, 13%, while in women 18-34 (2.8/9) the series posted its best number since Feb. 4.

At 9 PM, CW’s new drama Nikita (3.6 million) didn’t display the breakout potential Diaries showed in its premiere last year but did a good job holding onto its Diaries lead-in. It drew a bit more viewers than Diaries as well as last season’s premiere of Supernatural, which averaged 3.4 million viewers in the time slot last year.

Elsewhere, CBS’ Big Brother (2.5/8 in adults 18-49) was up 9% from last Thursday but was strongly affected by the game, dropping from 2.7/9 to 2.3/7 from the first to the second half-hour when the NFL game started. At ABC, summer drama Rookie Blue drew a 1.2/3 for its two-hour season finale, up 9% from last week’s low.