Clearly, HBO hasn't come close to draining the vein when it comes to "True Blood."
The cable outlet announced on Tuesday that Sunday's season four debut of its vampy drama grabbed a combined 6.4 million viewers for the evening, matching the series' high and gaining a 6 percent increase over season three's premiere.
The 8 p.m. premiere airing,drew 5.4 million total viewers, with the 11 p.m. encore grabbing up an additional million viewers.
In other cable ratings news, Syfy announced on Tuesday that its Saturday premiere of the movie "Swamp Shark" — which, much like "True Blood," chronicles a sharp-toothed predator in remote Louisiana — scored the highest ratings for the network in the adults 18-49 demographic for a Saturday original movie since the September 2010 airing of "Sharktopus."
"Swamp Shark" grabbed 773,000 viewers in the demo, and 2.2 million total viewers. The strong showing helped put Syfy in fifth place in the demo among cable networks in the demo.