So much for those theories that Survivor was going to be hurt hard by ABC, The WB, and UPN's aggressive attempts to grab a share of the Thursday night television viewership pie.

Two months into the new season, Survivor: Guatemala's ratings are down a bit from last spring's Survivor: Vanuatu edition, but, due to the fact that most of the three network's gains have come at the expense of NBC and Fox, the long-running CBS reality series has actually become more dominant in the Thursday 8PM ET/PT hour.

Last week's broadcast of Survivor: Guatemala's ninth episode was the show's highest rated episode yet. The November 10 broadcast averaged 18.98 million viewers, a 11.0/17 rating/share in households, a 6.9/19 in the Adults 18-49 demographic, a 8.3/20 in Adults 25-54, and a 5.0/15 in Adults 18-34 -- numbers that represented season highs in all five of the metrics.

The performance placed Survivor: Guatemala eighth in the weekly viewership rankings, behind only sweeps-fueled broadcasts of CSI, Desperate Housewives, NFL Monday Night Football, Without A Trace, Lost, Grey's Anatomy, and CSI: NY. Survivor: Guatemala placed slightly better -- sixth place -- among both the Adults 18-49 and Adults 25-54 weekly rankings.

The prior week's November 8 episode also performed well, averaging 18.28 million viewers, a 10.9/17 in households, a 6.6/17 in Adults 18-49, a 8.1/19 in Adults 25-54, and a 4.4/13 in Adults 18-34 -- numbers that, at the time, marked the season's best Adults 25-54 delivery and the show's best performance in the other metrics since Guatemala's September 15 premiere.

The two performances have continued a string of dominating Survivor broadcasts in which, due to the ratings decline of Fox's The O.C. and NBC's Joey/Will & Grace combo, Survivor: Guatemala has repeatedly beat or nearly beat the combined numbers of Fox, NBC, and ABC among total viewers and the Adults 18-49 and 25-54 demographics.

Survivor: Guatamala's season average of 17.81 million viewers places it seventh in the primetime season-to-date viewership rankings (the rankings exclude Guatemala's premiere episode -- the season's second most watched episode -- as the episode was broadcast a week before the official start of the 2005-2006 season.)