“Dexter’s” fourth season is off to a killer start.

Sunday’s season preem of the Showtime drama on delivered record numbers for the pay cabler. “Dexter’s” 9 p.m. debut brought in 1.52 million viewers, which makes it a series high for the serial killer drama starring Michael C. Hall. It also makes it the most-watched telecast on Showtime since at least 2004. The 11 p.m. encore of the seg brought in another 403,000 viewers.

What’s good for “Dexter” is also good for its skedmate “Californication.” The David Duchovny starrer hit a series-record 821,000 viewers in its third-season debut at 10 p.m., and its 10:30 p.m. repeat grabbed another 382,000 viewers.

The “Dexter” bow was up 25% from its third season opener last year (1.21 million), and it was up slightly over the show’s third season finale (1.50 million). “Californication’s” preem was up 57% over its sophomore season bow.