ABC had a lock on the most gripping live primetime action last week, and that paid off handsomely in the ratings race with a dominant, across-the-board victory.

The NBA Finals — this year pitting the Miami Heat against the Oklahoma City Thunder — easily won all three of its nights for ABC and is off to its best start in eight years. And the Alphabet had auds on the edge of their seats Friday too with daredevil Nik Wallenda’s high-wire walk across the precipice of Niagara Falls.

On the scripted side last week, TNT’s two-hour premiere of “Dallas” on Wednesday (1.5/5 in 18-49, 6.86m) became the most-watched cable series premiere of the calendar year. It had a fairly older skew, but still scored well with adults 25-54, as its 2.1/6 in the demo topped all other ad-supported scripted originals last week on both broadcast and television.

“Dallas,” “Falling Skies” (opening its second season) and “Rizzoli & Isles” gave the Turner net cable’s three top scripted originals for the week in total viewers and adults 25-54.

Overall for the June 11-17 frame, ABC cruised in adults 18-49 with a 3.0 rating/10 share, followed by NBC (1.6/5), Fox (1.5/5), Univision (1.2/4) and CBS (1.1/3). The Alphabet also won with ease in both adults 25-54 (3.3/9) and total viewers (8.3 million).

The NBA Finals on ABC claimed the top three spots in the program rankings. Thursday’s second game rated highest (7.1/22, 16.67m), logging the top same-night 18-49 score for any program since the April 2 college basketball championship game on CBS.

“Megastunts: Highwire Over Niagara Falls,” which aired live in much of the country from 9 to 11 p.m. Friday, averaged a 2.5 rating/9 share in adults 18-49 and 10.26 million viewers overall — the most-watched non-sports summertime Friday telecast on the Big Four (Memorial Day-Labor Day) in nearly seven years.

Viewership peaked in the 10:30 p.m. half-hour with a big 3.5/12 in 18-49, a 4.4/13 in 25-54 and 13.31 million viewers.

The top broadcast series for the week were NBC’s “America’s Got Talent” (3.0/8, 11.18m), Fox vets “Hell’s Kitchen” (2.8/9, 5.32m), “MasterChef” (2.7/7, 5.95m) and “So You Think You Can Dance” (2.5/8, 6.71m) and ABC’s “The Bachelorette” (2.3/7, 7.43m).

On cable, “Falling Skies” kicked off its second season Sunday (1.5/4, 4.46m), down 20% or more in most categories from its strong series preem of last year (which didn’t face the NBA Finals).

ABC Family’s “Bunheads” opened modestly Monday (0.6/2 in 18-49, 1.64m) behind the fifth-season preem of “Secret Life of the American Teenager” (0.8/2, 1.68m), which was down sharply year to year. (“Bunheads” did post nice demo gains on Monday of the current week, though.)

Disney Channel’s original Friday movie “Let It Shine” (0.9/3 in 18-49, 5.70m), becoming the calendar year’s No. 1-rated telepic across all core kid demographics. Pic, a re-imagining of the classic Cyrano de Bergerac story set in the contemporary world of hip-hop, rap and gospel music, drew 3 million kids 2-11, 2.6 million kids 6-11 and 2.3 million tweens 9-14.

Up against the NBA Finals, Thursday’s second-season preem of USA’s “Suits” (1.1/3 in 18-49, 3.47m) saw significant year-to-year ratings erosion, as did its lead-in, the sixth-season opener for “Burn Notice” (1.2/3, 3.87m); their year-ago bows didn’t oppose hoops action.

AMC’s second-season finale of “The Killing” (1.45 million viewers) gained week to week, but still came in well down from its rookie-season conclusion (2.32 million). And at HBO, the first-season finale of “Girls” averaged 1 million viewers.