CBS has closed out its victorious 1993-94 primetime Nielsens regular season with a narrow victory over ABC in April 11-17 results.The close finish reflects a season in which, had CBS not enjoyed a huge boost from the Winter Olympics, the two leading nets would have ended up within an estimated 0.2 rating points of each other (see story, page 1). It was generally a lackluster wrap-up to an otherwise rousing ’93-94 campaign , but the closing week did feature continued excellence from a couple of late-season additions, ABC’s “Thunder Alley” and CBS’ “Christy.” As usual, ABC paced the webs among adults 18-49. Those averages were: ABC, a 6.5 rating, 19 share; NBC, 5.7/16; CBS, 5.5/16; Fox Broadcasting Co., 4.4/13. Monday On April 18, the first night after the traditional 30-week season, NBC earned its first Monday victory in nine weeks thanks to “Fresh Prince” (10.9/19), “Someone Like Me” (10.6/18) and the Nicollette Sheridan-Gary Cole vidpic “A Time to Heal” (12.7/21), all slot winners. Fox made the night’s biggest news, however, when its get-there-first Menendez vidpic, “Honor Thy Father and Mother” (10.2/17), grabbed the best rating for a Fox vidpic and fourth-highest rating for any movie ever aired on Fox. Sunday CBS won Sunday for the 29th time in 30 weeks, losing only the night of the Super Bowl. Since that top-rated gridcast, CBS has won 78 of 80 Sunday half-hours. NBC’s “Lionheart” rerun took the 9-11 p.m. film competition among adults 18- 49. Earlier in the evening, “seaQuest DSV” ended a storm-tossed season by sinking to fourth in its slot for the seventh time in eight voyages. Saturday CBS limped home first, equaling its lowest regular-schedule Saturday share of the season. Fox zipped into second (first among adults 18-49) against listless web competition. “America’s Most Wanted” hit its best Saturday share since switching to that lineup in January. NBC’s “Empty Nest” fell to its lowest firstrun rating ever, “Nurses” to its worst firstrun rating in that slot and “Winnetka Road” to the net’s lowest regular-season rating in that hour since a “Live From Studio 8H” performing-arts spec in January 1982. Friday ABC earned its 27th Friday victory in the season’s 30 weeks, though CBS held at least a share of the lead till 10 p.m., when “20/20″ finally put the night away for ABC. “Diagnosis Murder” won its hour for the first time, sending “Family Matters” to its first slot loss to any competition besides the Olympics since Bob Hope’s 90th-birthday spec 11 months ago. Fox’s “X-Files” is taking off in the 9-10 p.m. hour, last week rising to its highest rating thus far and Fox’s best rating in that slot. “X-Files” even beat ABC’s strong “TGIF” sitcoms among adults 18-49. Thursday NBC took the night but CBS won the 8-9 p.m. hour in households with “Christy.” In its second Thursday try, “Christy” lost 12% of its week-one rating but overtook the slot’s weakened competition. A firstrun “The Simpsons” could do no better than third in households against “Christy” and a “Mad About You” rerun. Chances of survival are snapping shut for “Traps,” which last week snagged CBS’ worst Thursday 10 p.m. rating in three months. Wednesday ABC breezed again, with “Thunder Alley” continuing to rattle the competition, last week improving on its “Home Improvement” lead-in. “These Friends of Mine” lost 21% of its “Improvement” lead-in but is still a promising late-season performer. “Law and Order” is up 26% over year-ago ratings since it began running against all-newsmag competition (ABC’s “Turning Point” and CBS’ “48 Hours”) six weeks ago. Tuesday ABC’s all-rerun lineup controlled the night, though CBS’ “Rescue 911″ took the 8 p.m. hour for the fifth week in a row. In its second try, “South Central” slipped in rating by 8% and is now within a share of what slot predecessor “Monty” averaged there. “South Central” ran 11% ahead of what Fox averaged in the slot through the season. Monday CBS prevailed, thanks in part to a Rush Limbaugh guest spot on “Hearts Afire, ” which gave CBS its first rating improvement over a “Murphy Brown” lead-in since September ’92 (Daily Variety, April 13).