The Portland auditions were seen by 18.2m (5.9) for Fox in the 8pm hour.
Howie Mandel's Mobbed then pulled in 7.9m (2.9), growing hugely on its last instalment on January 11.
But despite aiding Mobbed, Idol's audience is down considerably on the equivalent episode last year, by 34% in the 18-49 adult demos.
Struggling NBC comedies Whitney (4.4m/1.7) and Are You There, Chelsea? (4.1m/1.7) rallied. Afterwards, a double repeat airing of Law & Order: SVU secured 4.8m (1.1) at 9pm and 5.8m (1.6) at 10pm.
Super Bowl's Greatest Commercials, CBS's only original offering of the night, grabbed 8.7m (2.1) at 8pm. Criminal Minds (8.2m/2.1) and CSI (7.4m/1.5) followed.
Wall-to-wall reruns of The Middle (4.9m/1.2), Suburgatory (4.2m/1.2), Modern Family (7.7m/2.7) and Happy Endings (5.3m/1.9) aired on ABC
Even with the lack of competition, The CW's One Tree Hill (1.5m/0.7) and Remodeled (750k/0.3) showed no gains.