Nancy Lopez, the sport's most dominant rookie ever, cruised to two-under-par 70 yesterday and won the Ladies Professional Golf Association Championship. Her 72-hole total of 275 and her 13-under-par performance established two records for this major championship.

Her six-shot margin over Amy Alcott brought the 21-year-old phenomenon her first major title, a record-matching fourth straight triumph and her sixth victory this year.

"Great, super, fantastic, every good word I can think of," said Lopez.

Her father, Domingo Lopez, made the trip from their hometown, Roswell, N.M., blew her kisses as she made great shots and answered his kisses in kind, and he greeted her with a hug and kiss at the finish.

Lopez, 21, said she plans to play six of the next eight weeks in a bid to become the sport's all-time money champion as a rookie.

"And now that I've won four in a row, I'd like to break the record with five straight," she said.

Lopez was informed she had played the last 41 holes on the 6,250-yard Jack Nicklaus Golf Center course with only one bogey. She grinned and said, "Sounds good."

Lopez, already considered by her peers to be the greatest putter ever to join the women's tour, said, "I owe it to my putter. I really did play consistently all week and really putted well."

Lopez spent three years as a teen-ager developing her putting, spending as much as two hours daily on her green game.

Runner-up Alcott praised the style of the new superstar, saying, "I've never met a person who accepts what she does with such humility and class."

Lopez earned $22,500, pushing her money winnings to $62,250 for her last four tournaments and $118,984 for the season.

Alcott, the 1975 LPGA rookie of the year, closed with 71 for 281 and picked up a check for $14,650. She used an eagle on the ninth hole and three birdies to finish second.

Judy Rankin matched par yesterday and was alone in third place at 283. JoAnne Carner, last week's winner at Toronto, had 71 for 284 and fourth place.

Jo Ann Washam was fifth with 75-285.

With her victory, Lopez:

Became the earliest winner of $100,000 in a single season on the LPGA tour. Rankin set the previous record of July 12, in 1976.

Tied the consecutive tournament victory records shared by Mickey Wright (twice), Kathy Whitworth and Shirley Englehorn.

Joined Donna Young, Jane Blalock, Carner, Whitworth and Rankin as $100,000 LPGA winners in one year.

Extended her own record of titles for a first-year player, either man or woman. Bob Murphy and Jerry Pate hold the men's rookie mark. Several women had shared the LPGA record of one rookie victory.

Moved within range of the rookie money-winning record for professional golf. Pate won more than $153,000 two years ago. She has $142,000 since joining the LPGA last July, so needs less than $12,000 in the next eight events to break the record.

Her total snapped the previous LPGA championship record of 273 Mary Mills posted in 1964. Her underpar figure shattered the previous figure of nine under by Chako Higuchi a year ago. This year Higuchi finished 73-290 for 13th place.

Lopez registered her 11th round of pat or better in her last 13 rounds to stow away this major championship unchallenged. She posted nine straight pars on the front side and rammed in three birdies to offset a single bogey on the closing nine.

Alcott moved within four shots of the lead at the ninth hole when she knocked in a six-foot eagle putt but that was as close as anyone would get the rest of the way.