Continuing its multimedia momentum, the 2015 NCAA Division 1 Men’s Basketball Championship set linear TV and streaming marks through the first Saturday of the tournament.

The event, airing on CBS, TBS, TNT and truTV, netted its all-time highest rating for the first Saturday since it expanded to four telecast windows across the day in 1991, boosting the tourney to a record 6.5 overnight rating/14 share average through March 21, according to Nielsen. That was 8% greater than the 6.0 average a year ago, the previous record-holder.

For its part, digital platform NCAA March Madness Live has delivered a record-setting 47 million live video streams through Saturday, up 7% from last year, according to Conviva and Adobe Analytics.

Saturday’s contests – featuring No. 1 Kentucky and the upset of the East’s top seed Villanova -- averaged a 7.4 overnight rating/17 share, up 14% compared to a 6.5/14 in 2014, according to Nielsen metered market data. That was the best first Saturday performance since the 1991 change.    

The first primetime telecast window  -- 5:15 p.m. to 9:45 p.m. (ET) -- on Saturday scored a 10.3/23 share, the highest rating for the game window since the introduction of the format. It was up 20% from an 8.6/19 last year.

The second primetime window -- from 7:45 p.m. to 12:30 a.m. averaged an 8.9/17 to tie 1993 as the highest rating for the game window of all time with the format.  That performance marked a 9% jump from the 8.2/15 in the corresponding telecast window in 2014.

Coverage of North Carolina State’s 71-68 win over Villanova (pictured) -- the biggest upset in this year's tournament to date -- bridged the primetime windows.

Showcasing Kentucky’s 64-51 triumph over Cincinnati, the second daytime telecast window from 2:45 p.m. to 5:15 p.m. averaged a 6.7/16, the best average since 2007, and 29% ahead of last year’s pace.  

Additionally, the NCAA tourney grossed a record 82 million total social impressions across Facebook, Twitter and Instagram through Saturday for a 35% increase over 2014.