ABC’s critically adored new show “Ugly Betty” is looking pretty good after a strong premiere last night.

The charming adaptation of a Colombian telenovela averaged a 4.9 in adults 18-49, according to Nielsen overnight ratings, finishing second in the 8 p.m. hour to CBS’s “Survivor.”

That helped ABC to its second straight Thursday night victory, this one a lot more narrow than its first, averaging a 6.2 rating and 16 share to CBS’s 6.0/16. Last week ABC averaged a 7.2/19 to CBS’s 6.0/16.

“Betty,” which recorded the fifth-best premiere for a new show this season, built 25 percent from its first half hour to its second, going from a 4.2 to a 5.6. It became just the third debut this season to grow in its second half, joining NBC’s “Heroes” and CBS’s “Jericho.”

And it even finished ahead of CBS’s “Survivor” among households in the timeslot, averaging a 10.7 rating to the latter’s 9.6. “Survivor” did narrowly edge “Betty” in total viewers with 16.6 million to the latter’s 16.1 million, but the reality show dipped 9 percent week to week in 18-49s.

“Betty” surely got a boost from people clicking in early in anticipation of 9 p.m. smash “Grey’s Anatomy,” which once again took first in its timeslot among 18-49s with a 9.4 rating, 1.5 ahead of CBS’s “CSI.” But “CSI” did bounce ahead in total viewers this week, drawing 23.5 million to “Grey’s” 23.3 million.

“Betty” did extremely well among women 18-49 and women 18-34, where it won the timeslot. ABC certainly looks smart for moving the show from little-watched Friday to Thursday late this summer, as it could be a steady builder.

Most likely CBS and ABC will trade wins on the night over the coming weeks, as both their schedules settle in. Though ABC’s new “Six Degrees” finished ahead of CBS’s new “Shark” at 10 p.m. for the second week, “Degrees” was down 24 percent from its premiere, from a 5.4 to a 4.4. “Shark” stayed steady at a 4.2, but both shows lost a lot of their lead-in. “Shark” drew nearly 4 million more total viewers than “Degrees’” 10.8 million.

Both ABC and CBS had hoped for more out of the timeslot, where NBC once again won easily in 18-49s with “ER’s” 6.1.

Meanwhile, for the night, ABC and CBS were followed by NBC’s 4.3/11 average. Univision was fourth at 2.0/5, and Fox and the CW tied at 1.9/5.

CBS’s “Survivor” was first at 8 p.m. with a 5.8, followed by “Betty” at 4.9. NBC’s “My Name is Earl” dipped to a 3.4, down from last week, and lead-out “The Office” bettered “Earl” for the second time ever, and the second straight week, with a 3.7. Two episodes of Fox’s “’Til Death” were fourth at 2.4, followed by a 2.2 for CW’s “Smallville” premiere and a 2.1 for Univision’s “La Fea Mas Bella.”

At 9 p.m., “Grey’s” led with a 9.4, followed by “CSI” at 7.9, NBC’s “Deal or No Deal” at 3.2, Univision’s “Barrera de Amor” at 2.3, its best rating in weeks, CW’s “Supernatural” at 1.6 and Fox’s “Celebrity Duets” at 1.5.

At 10 p.m., NBC’s “ER” led at 6.1, followed by “Degrees” at 4.4, “Shark” at 4.2 and Univision’s “Aqui y Ahora” at 1.8.

Among households, CBS barely slipped past ABC, at 11.1/17 to 11.0/17, followed by NBC’s 6.8/11, Fox’s 3.2/5, CW’s 2.6/4, and Univision’s 2.4/4.