Even though Fox’s “House” and “American Idol” are on the same network, they seemed like rivals in the third week of sweeps.

The medical drama last week continued to gain ratings ground on the reality behemoth, which has seen audience erosion during the latter half of the season.

“House” tied “Idol” for the first time, according to preliminary data from Nielsen Media Research. Ratings analysts for rival networks found themselves in the unusual position of cheering on Fox’s “House,” which has been closing the gap on “Idol” in recent weeks.

“Die `Idol’ die!” wrote one network analyst in an email.

Of course, “House” benefits enormously from its “Idol” lead-in. After the national ratings came in, which factored in Fox’s relatively standard two-minute overrun from “Idol,” the universe righted itself and “Idol” had a 9.4 ratings among adults 18-49, compared with “House’s” 9.2. “House” still posted the highest retention of an “Idol” lead-in by any show to date.

Elsewhere during the week, reality series performed strongly, with the exception of the “Survivor” finale.

The CW’s “America’s Next Top Model” concluded its eighth cycle with a 3.0, tying its best rating in more than three years.

ABC’s “Dancing With the Stars” results show had its highest rating for the current installment (4.8). Also on ABC, “The Bachelor” (4.0) had its best showing in more than a year in key demos.

On CBS, however, “Survivor” had its lowest-rated finale and reunion show to date (4.6 and 4.1, respectively), but still ranked No. 2 for the night Sunday.

Among other shows, CBS’ “King of Queens” concluded its nine-year run with its highest rating in more than five years (5.2), but the network’s telecast of the “Country Music Awards” had its lowest rating in at least 17 years (2.7).

As for the sweeps horserace, for the first three weeks Fox continued to lead with 4.0 (down 9 percent year-to-year). ABC was second with 3.5 (up 3 percent), CBS third with 3.2 (down 16 percent), NBC fourth with 2.4 (down 25 percent), Univision fifth with 1.6 (up 33 percent) and The CW sixth with 1.3 (up 8 percent compared with UPN and WB).