Stargate SG-1‘s ratings held steady in Season Nine’s second week, with “Avalon, Part 2” earning a 2.1 average household rating. But viewership for lead-out series Stargate Atlantis and Battlestar Galactica fell from their season premieres, with SCI FI Friday’s anchor show suffering a significant drop.

Stargate SG-1 led off the night once again in the 8 p.m. Eastern/Pacific time slot. The second installment of the 3-part premiere drew more than 2.6 million viewers with the 2.1 rating, holding on to viewership from the season premiere.

The Stargate Atlantis episode “The Intruder” earned a 2.0 rating at 9 p.m., down 10 percent from last week’s premiere.

At 10 p.m. Battlestar Galactica suffered a 23 percent drop-off from last week’s highly publicized and widely reviewed season premiere. The episode “Valley of Darkness” held its lead-in audience for a 2.0 household rating. It is the lowest rating to date for the series, which premiered in January.

The three series earned ratings of 1.2 (SG-1), 0.9 (Atlantis), and 0.7 (Galactica) for their late-night reruns.

SCI FI also began reruns of FOX’s cancelled series Firefly at 7 p.m. “Serenity, Part 1” earned a solid 1.3 rating outside of primetime.

New episodes of Stargate continue this Friday at 8 p.m. Eastern/Pacific on The SCI FI Channel!