This NCAA basketball bonanza kicks off with the First Four Round – four games in each tournament to determine the final four teams in the Round of 64. It’s the last puzzle piece before the March Madness bracket is complete.

Now, eight teams will go head-to-head to secure the final vacant spots in the 2025 NCAA Tournament bracket. On Tuesday and Wednesday, March Madness will officially begin with the First Four matchups.

Sunday's eight second-round games in the NCAA men's tournament will complete the Sweet 16. A breakdown of the matchups and what to watch.