Media people tabbed “Bionic Woman” as either a potential breakout or a potential bomb, but few probably expected it to do what it did last night. The NBC drama’s premiere outdrew the debut of ABC’s highly anticipated “Grey’s Anatomy” spinoff “Private Practice” and nearly boosted NBC to No. 1 on a night where it has long struggled.

“Bionic” averaged a 5.5 adults 18-49 rating at 9 p.m., according to Nielsen overnights, 8 percent better than “Practice” still-solid 5.1 rating.

NBC came very close to besting ABC on the night, averaging a 4.1 rating and 11 share to the latter’s 4.2/11. It was NBC's top Wednesday premiere week rating since 2004 and was up 37 percent over its 3.0 rating for premiere week last year.

“Bionic,” which is now the fall's top new premiere and NBC's best Wednesday series premiere since "The West Wing" in 1999, built from its first half hour to its second among 18-49s, while “Practice” was flat.

“Bionic” is a remake of the 1970s show about a woman who becomes part machine thanks to a life-saving procedure that gives her superhuman strength. NBC pumped the show with a heavy marketing campaign designed to appeal to the same viewers who made “Heroes” into a hit.

Indeed, that show is strong with the younger male demos, and “Woman” won its timeslot in men 18-34 and 18-49 last night, while “Practice” was No. 1 in adults 18-34 and the major female demographics. “Practice” also topped “Bionic” by 600,000 in total viewers, drawing 14.2 million.

Yet perhaps as surprising as “Bionic’s” performance was NBC’s “Life,” which won its timeslot at 10 p.m. leading out of “Bionic” despite being dismissed by media buyers and many critics. 

The show about a cop who rejoins the force after a long incarceration for a crime he did not commit averaged a 4.1 in 18-49s, besting CBS’s returning “CSI: NY,” which had its lowest-ever premiere at 3.7, and ABC’s much-touted “Dirty Sexy Money,” which averaged a 3.6. “Life” and “Money” both fell 11 percent in their second half hours.

Meanwhile, four shows that debuted last week all saw declines in week two. Fox’s “Back to You” slipped 10 percent from a 3.1 to a 2.8, while CBS’s “Kid Nation” fell 7 percent, from a 3.0 to a 2.8. Those are not overly steep and to be expected against new competition.

In the 9 p.m. hour, against “Bionic” and “Practice,” the news was worse for Fox and the CW. Fox’s “Kitchen Nightmares” slipped 23 percent from a 3.1 to a 2.4, while CW’s “Gossip Girl” slid 27 percent among the network’s target demographic of 18-34s, from a 2.2 to a 1.6.

For the night, CBS finished third behind ABC and NBC at 3.3/9, Fox fourth at 2.5/7, CW fifth at 1.8/5 and Univision sixth at 1.6/4.
 
ABC began the night in the lead with a 4.0 rating at 8 p.m. for its “Dancing with the Stars” results show, followed by CBS with a 2.8 for “Nation.” NBC and Fox tied for third that hour at 2.6, NBC for “Deal or No Deal,” Fox for “Back to You” (2.8) and “Til Death” (2.4), with the CW fifth with a 2.4 for “America’s Next Top Model” and Univision sixth with a 1.2 for “Amar sin Limites.”
 
NBC took the lead at 9 p.m. with its 5.5 for “Bionic,” with ABC second with a 5.1 for “Practice.” CBS was third with a 3.5 for “Criminal Minds,” Fox fourth with a 2.4 for “Kitchen Nightmares,” Univision fifth with a 2.2 for “Destilando Amor” and CW sixth with a 1.2 for “Gossip Girl.”
 
At 10 p.m. NBC was first with a 4.1 for “Life,” while CBS moved to second with a 3.7 for “CSI: NY.” ABC was third with a 3.6 for “Money” and Univision fourth with a 1.5 for “Don Francisco Presenta.”
 
Among households, ABC led its third straight night with a 9.4 average overnight rating and a 15 share. CBS was second at 7.0/11, NBC third at 6.8/11, Fox fourth at 3.8/6, CW fifth at 2.4/4 and Univision sixth at 2.1/3.