NBC refused for months to comment on speculation that George Clooney would return in the final episodes of long-running hospital drama “ER,” but enough people got the message from unconfirmed reports.

Clooney’s appearance on last night’s “ER,” his second return trip back to the show since he left the cast in 1999, boosted the program to a 3.9 adults 18-49 rating, according to Nielsen overnights, up 11 percent over last week’s 3.5 and its best rating since October, tying a season high.

NBC’s decision not to overhype Clooney’s return may have cost the show some viewers. It attracted 10.7 million total viewers, finishing 1.1 million behind timeslot winner “Eleventh Hour” on CBS, but it was still the show's best outing in more than two years, since February 2007.

That was a fraction of the 32 million a week who watched the show at its peak during the mid-1990s, when Clooney, Julianna Margulies, Noah Wyle and Eriq La Salle headlined the cast.

All three appeared on last night’s episode, which continued the cast roll call from the past 15 seasons. Others who have previously returned include Laura Innes, Alex Kingston and Anthony Edwards, which is pretty impressive considering his character died a few years ago.

The series finale airs in three weeks.

As a reminder, all ratings are based on live-plus-same-day DVR playback. Seven-day DVR data won’t be available for several weeks. Twenty-eight percent of Nielsen households have DVRs.
 
CBS was first for the night among 18-49s with a 3.7 average overnight rating and a 10 share. ABC was second at 3.5/9, NBC and Fox tied for third at 3.1/8, Univision fifth at 1.8/5 and CW sixth at 1.3/4.
 
At 8 p.m. CBS led with a 4.1 for “Survivor,” with Fox second with a 2.8 for “Bones.” ABC was third with a 2.1 for “Ugly Betty,” Univision fourth with a 1.8 for “Cuidado con el Angel,” NBC fifth with a 1.7 for a repeat of “My Name is Earl” and a new “Kath & Kim” (1.7) and CW sixth with a 1.6 for “Smallville.”
 
ABC took the lead at 9 p.m. with a 4.9 for “Grey’s Anatomy,” while CBS fell to second with a 4.2 for “CSI.” NBC was third with a 3.7 for “The Office” (4.0) and “30 Rock” (3.3), Fox fourth with a 3.5 for “Hell’s Kitchen,” Univision fifth with a 2.0 for “Mañana Es para Siempre” and CW sixth with a 1.1 for “Supernatural.”
 
At 10 p.m. NBC’s moved ahead with a 3.9 for “ER,” followed by ABC with a 3.4 for “Private Practice.” CBS was third with a 2.8 for “Eleventh Hour” and Univision fourth with a 1.5 for “Rosa de Guadalupe.”
 
Among households, CBS came in first for the night with an 8.3 average overnight rating and a 13 share. ABC was second at 6.7/11, Fox third at 5.2/8, NBC fourth at 4.6/7, Univision fifth at 2.1/3 and CW sixth at 2.0/3.