FX’s decision to slot Guillermo del Toro’s new vampire-virus drama “The Strain” on Sunday nights paid off with a good ratings performance for its premiere.

Also of note on Sunday in cable were sluggish second-season premieres for Showtime’s “Ray Donovan” and “Masters of Sex,” both of which drew their smallest regular-timeslot audiences to date — though each enjoyed stronger lead-in support during their first seasons.

According to Nielsen estimates, “The Strain” averaged a 1.2 rating in adults 18-49 and 3 million viewers overall for its initial telecast Sunday night at 10. The demo rating matches TNT’s “The Last Ship” as cable’s top premiere of the summer, and is considerably better than FX saw this year with “Fargo” in April (0.8) or “Tyrant” in June (0.6).

The expanded 100-minute premiere of “Strain” was television’s No. 1 show of the night in men 18-34 (1.4 rating/5 share) and stood as the No. 2 cable show of the night in men 18-49 (1.4/4), behind HBO’s “True Blood.”

It figures to generate strong DVR playback too, as FX’s dramas have consistently done. The network opted against touting the same-night numbers for “The Strain,” instead planning to wait until “Live + 3” numbers are released by Nielsen later this week.

Sunday has become the signature night for acclaimed cable series, a trend that began with HBO’s “The Sopranos” and continues today with the marquee series on HBO, Showtime, AMC and others. Until now, FX had traditionally stuck with weeknight timeslots for its series, including “Sons of Anarchy,” “Justified” and “American Horror Story.”

The regular-timeslot competition for “The Strain” in the 10 p.m. hour on Sunday included HBO’s “The Leftovers,” Showtime’s “Masters of Sex,” AMC’s “Halt and Catch Fire” and TNT’s “Falling Skies.”

“The Strain,” from FX Productions, was co-created and is executive produced by del Toro and Chuck Hogan, who teamed to pen the pilot script. Del Toro directed the episode.

Carlton Cuse serves as executive producer/showrunner and writer. Gary Ungar also serves as executive producer.

The high-concept thriller tells the story of Dr. Ephraim Goodweather, the head of the Center for Disease Control Canary Team in New York City. He and his team are called upon to investigate a mysterious viral outbreak with hallmarks of an ancient and evil strain of vampirism. As the strain spreads, Eph, his team, and an assembly of everyday New Yorkers, wage war for the fate of humanity itself.

In other cable ratings news on Sunday, Showtime’s second-season premiere of “Ray Donovan” averaged 1.22 million viewers — below both its series premiere last year (1.35 million) and its first-season finale in September (1.41 million). It’s worth remembering, though, that “Donovan” aired behind the net’s top show, “Dexter,” last summer; the serial killer drama opened with 2.5 million and ended its run with 2.8 million.

Similarly, “Masters of Sex” averaged 825,000 viewers with its 10 p.m. premiere Sunday — below the 998,000 it opened to last fall and the 1.21 million for its season finale. But it aired behind Showtime’s No. 2-rated program, “Homeland,” whose series premiere drew 1.9 million, and its finale did 2.4 million.

And at Lifetime, the second-season finale of “Devious Maids” did a 0.79 rating in adults 18-49 and 2.23 million viewers overall. This season didn’t rate as high as last year’s, but it picked up steam late, with the finale rising 16% week to week in 18-49 (from 0.68) and nearly 80% over two weeks ago (0.44).

In its third week, HBO’s “The Leftovers” dropped to 1.38 million viewers for its regular-timeslot episode, down from 1.55 million last week and 1.77 million for its premiere.