The games Thursday on CBS, TBS, TNT and truTV averaged a 5.8 overnight rating and 14 share. The networks say that was up 4 percent from 2012.
This is the third season of CBS and Turner's 14-year, $10.8 billion contract to televise every game of the tournament in its entirety, a change in approach that so far has been a ratings success.
Ratings represent the percentage of all homes with televisions tuned to a program. Shares represent the percentage of all homes with TVs in use at the time. Overnight ratings measure the country's largest markets.