The opening day of the NCAA men's tournament on Thursday averaged 9.1 million viewers across CBS, TBS, TNT and truTV.
That number, up 6% from last year, makes it the most-viewed opening day of play on record.
The matchup between Arkansas and Kansas averaged 6.36 million viewers on CBS, the largest audience for a first-round game since 2011.
The early primetime window on Thursday averaged a 5.8 rating with 12.17 million viewers.