ABC hopped past CBS to win a tough Easter week primetime Nielsen race.Relying on its midweek strength –”Home Improvement,”"Roseanne” and a solid start for the new sitcom “These Friends of Mine”– ABC rolled to its fourth straight weeklong win and its 13th of the season. That’s the most weekly victories for ABC since 1978-79, with two weeks remaining in the official, 30 -week ’93-94 campaign. CBS got a solid premiere of its own, as “Christy” chalked up the Eye’s strongest Sunday 8-10 p.m. non-Olympics share in five tries. Still, ABC countered with “These Friends,” grabbing the week’s third-highest rating overall, and “Sister, Sister,” which attracted initial ratings surges with its Friday double premiere. Last week’s Nielsen action saw ABC dominate among adults 18-49, marking the 19 th time in the season’s 28 weeks that the Alphabet web has prevailed in that demo. Last week’s averages were: ABC, a 7.5 rating, 21 share; CBS, 6.2/17; NBC, 5.4/15; Fox Broadcasting Co., 4.4/12. NBC endured a rough holiday weekend and stumbled to its second-lowest regular-season non-Christmas-week rating. Sunday CBS overruled “The Ten Commandments” with “Christy,” which dominated its slot in households and earned a promising 23 share among adults 18-49. CBS notes that , despite Easter and daylight savings drains on viewership levels, “Christy’s” 17.7 rating nearly equals the Jan. 1, 1993, premiere rating of “Dr. Quinn, Medicine Woman” (18.2). “Ten Commandments” dropped 13% from its previous rating last Easter, making it the lowest “Commandments” rating since 1987. The epic, in its 15th network run, still commanded Sunday night among adults 18-49. NBC is hemorrhaging again on Sundays, last week suffering its lowest regular-season Sunday rating since April 15, 1990. The latest culprit was “The Marcus Nelson Murders,” the “Kojak” pilot repeated in homage to Telly Savalas, NBC’s lowest-rated Sunday pic since the Dec. 12 “The Jetsons” (7.2/11). “Nelson” first aired on March 8, 1973, capturing a 19.8/36. At Fox, “Your Favorite Commercials” rang up the weblet’s best Sunday 7-8 p.m. share since November. Saturday The Duke-Florida NCAA semifinal game took the night, though down 13% from last year’s comparable game. ABC finished a close second when “The Commish” nailed its best share ever and second-best rating. Also, the rerun vidpic “In Defense of a Married Man” earned the net’s top score in the Saturday 8-10 p.m. slot since a Feb. 5 skating spec. It did so with a fourth-place 10 share among adults 18-49. NBC’s getting a bumpy ride down “Winnetka Road,” last week crashing to the web’s worst regular-season rating in the Saturday 10 p.m. hour in more than 12 years (since “Live From Studio 8H’s” 3.3/5 Jan. 16, 1982). Fox finished second among adults 18-49 for the third consecutive night. Friday Regular leader ABC got a boost from the strong initial appeal of “Sister, Sister.” With its twin episodes, “Sister” scored ABC’s best Friday 8:30-9 p.m. leadout performance (up 11% from “Family Matters’ ” rating) since last June 25 and best Friday 9:30-10 perf (up 3% from “Step By Step”) since Christmas Eve. NBC stalled in fourth place for the night, as “Viper” sputtered to its worst rating ever and “Perry Mason” collapsed to the lowest regular-season rating in that vidpic series’ history. “Mason” did help drag rival sleuther “Burke’s Law” to its lowest rating yet. “Law” was coming off a preemption-heavy stretch that saw it air just twice in the previous seven weeks. Fox’s Friday regulars are headed in opposite directions — the developing hit “X-Files” snooped out its highest regular-season share thus far, but “The Adventures of Brisco County Jr.” got hog-tied for its lowest firstrun rating. Thursday NBC took an easy win, though a rerun “Mad About You” got nipped by a firstrun “Simpsons,” the first time the Fox series has won its slot since December. The premiere of “Traps” snared CBS’ top share in the Thursday 10 p.m. hour in the five weeks since the Winter Olympics, though “Traps” stayed third in the time period against all-newsmag competition. Wednesday ABC won this night by a monster 18 shares among adults 18-49. A double dose of “Home Improvement” for a fourth week in a row did the trick, with the 9-9:30 installment equaling the hit series’ best household share. “These Friends of Mine” started its run in the 9:30 slot by retaining 79% of its “Home” lead-in rating, compared to 82% for slot regular “Grace Under Fire.” It was ABC’s highest-rated premiere in that half-hour since “The Slap Maxwell Story” reported an 18.2/30 on Sept. 23, 1987. As for ABC’s Wednesday rookie heroes, “Thunder Alley” continues to get meaty numbers in the middle of the network’s “Home Improvement” sandwich, but “Turning Point” veered into second place in the 10 p.m. hour with its lowest rating yet. Still, “Turning” left rival newsmag “48 Hours” far behind. Tuesday ABC took control after CBS’ “Rescue 911″ drove off with the 8-9 p.m. hour for the fourth timein five tries, while “X-Files” discovered Fox’s second-best rating in the Tuesday 8-9 p.m. hour in 10 weeks. Monday CBS swept the night’s half-hours as ABC suffered its lowest Monday-pic rating since Aug. 31, 1992 (Daily Variety, March 30). NBC’s airing of the HBO movie “And the Band Played On” earned the Peacock web’s strongest Monday-pic adults 18 -49 rating since Nov. 8. Each rating point represents an estimated 942,000 households, or 1% of the country’s TV homes. The share is the same sort of percentage, except that it’s measured against only the households in which TV is being watched during the timeslot involved.