Friday's interview with pop singer Rihanna sent ratings for ABC's "20/20" soaring.

The newsmagazine notched a 2.7 rating/9 share among adults 18-49 at 10 p.m. Friday, dramatically higher than the show's usual Nielsen number (in recent weeks, a 1.6). It was by far the top-rated show of the night in the key demographic, and the best adults 18-49 performance by the newsmag in nine months.

The chat proved particularly potent with viewers 18-34, giving "20/20" its best ratings in that demo (2.3/9) in nearly three years. 

Among all viewers, "20/20" was seen by 8.18 million people, winning its 10 p.m. timeslot by a hair over CBS's "Numbers" (8 million). NBC's 9 p.m. installment of "Law & Order" was Friday's No. 1 show in viewers, bringing in 8.4 million pairs of eyeballs.

Fox dumped its regular Friday lineup of "Dollhouse" and comedies, and while ratings went up, the network still had to settle for a fourth-place finish.

Meanwhile, the CW's "Smallville" continues to improve the network's Friday fortunes. It was the top-rated show in adults 18-34 in the 8 p.m. timeslot, scoring season-high numbers in the CW's core demo.