If the 1950 Philadelphia Phillies who got to the World Series were called the Whiz Kids, then the 1980 Phils, who are now halfway to winning that world championship, may become known as the Wizard Kids.

Again tonight, for the fourth consecutive time in a postseason game, the Phils staged a marvelous big-inning rally to win, this time 6-4 over the stunned Kansas City Royals. After winning only one Series game in 93 years, the Phils now have won two in 27 hours.

This night, the Phils scored four runs in the eighth inning to take a two games to none lead in this 77th classic. The Phils' uprising came against the best relief pitcher the Royals have to offer, Dan Quisenberry, the submariner who won or saved 45 games in the regular season, but got depth-charged and sunk this time.

"I thought we had it in hand," said Royal Manager Jim Frey. The Phils, playing unconsciously in this streak of late-inning blitzes, thought otherwise.

Before 65,775 howling folks in Veterans Stadium, the Phils treated Quisenberry as though he were throwing up softballs underhanded.

Before that Philadelphia eighth, the Royals had built a seemingly safe 4-2 lead against winner Steve Carlton, tattooing him for 10 hits and getting 18 men on base against the game's best southpaw. But the Phils had heartthrobs aplenty in store for their faithful -- two in particular: supersub Del Unser, who fueled the rally with a pinch hit double, and superstar Mike Schmidt, who hit the game-winning double.

That rally was a textbook example of how every element in a big inning leads to another as the pitcher and his defense seem to be sinking in quicksand. Bob Boone began the heroics by battling Quisenberry -- perhaps the best control reliever in baseball -- through 10 pitches for a walk.

Next came Unser, the 14-year journeyman who has found a home here as a jack of all trades, master of many.

"Del is unreal," exclaimed Schmidt. On Sunday, it was Unser who got the pressure-chocked two-out eighth-inning single that tied the Phils with Houston. "The guttiest hit I've ever seen," said Schmidt. And tonight, it was Unser who put K.C. in terminal trouble as he lashed a double to the wall in left-center.

Far more than scoring the sliding Boone, that double changed the whole strategy and shape of the inning. The next hitter, Pete Rose, now had a simple job: advance the runner. Which he did with a grounder to third. And, because of Unser, the batter after Rose, Bake McBride, also was thrown into a glorious rich-with-promise situation: the infield was drawn in.

McBride, a chop hitter anyway, beat Quisenberry's sinker into the turf, the easiest assignment a hitter could ask. The ball carried over the head of Frank White for a game-tying hit on what normally would have been a routine out.

Suddenly, the Phils could go for the kill. They have learned that knack. On Saturday, down two runs, they scored three in the eighth. On Sunday, down three to Nolan Ryan, they scored five in the eighth. On Tuesday here, down four to 20-game winner Dennis Leonard, they scored five in the third and never trailed thereafter. And now, two down in the eighth against the Quiz, they scored four.

"We are so confident once a big inning starts," said Unser. "Now, we expect it to happen."

"We're playing like world champions," explained Schmidt.

Throughout his career, Schmidt has been a terrible postseason clutch hitter. He brought a sub-.200 post-season average with him to the plate against Quisenberry, who is just the sort of nibbling, teasing sinkerballer who eats him alive. But Schmidt has been learning from Unser.

"On Sunday, I struck out at a time when it looked like that might kill our season," said Schmidt; "and before I could go back to the dugout and slam the bat in the rack, Del had tied the game with a hit. The game humbles you. You have to accept the fact that sometimes you're just a high-paid spectator."

Finally, Schmidt stopped being a watcher and became a doer. He lashed a long liner to right-center. It might be more knightly to say that Schmidt -- a prince among hitters -- struck an uncatchable blow. In truth, a good outfielder would have flagged it down on the warning track. In fact, Jose Cardenal, in his fleet youth, would have caught it. But Cardenal is no longer young. He is the Royals' Unser, a solid pro now playing in spots and trying to hide the rust. He gave up on the ball too soon. No matter what, he should have tried for the catch. But he didn't. A Series may have turned in that instant when he decided to go for the safe, nobody will notice carom.

McBride, a right fielder himself, anticipated a catch and waited between bases. But then he turned on the jet, beating the relay to the plate for the winning run.

As a final footnote to the internal mechanics of game-transforming rallies,

Schmidt took third on the throw home. That brought the infield in again. And rookie Keith Moreland's liner toward the normal shortstop position was suddenly a clean hit for an insurance run.

The Royals will have much to rue from this game, many decisions to ponder. Starter Larry Gura, who retired the first 13 Phillies, took himself out of the game, in effect, after six innings and only 82 pitches. That meant that Quisenberry had to start the seventh inning, instead of being called in to get only a few batters.

"Gura said he just didn't have his fast ball any more," said Frey. "He came to me and more or less told me he had run out of gas."

That won't win any medals for fortitude.

By contrast, Carlton, who needed three ninth-inning outs from saving reliever Ron Reed, was the absolute opposite. He had nothing all night. Thanks to 10 hits, six walks and two errors, he was surrounded by more runners than he normally sees in two starts.

"It was the damn baseballs," said Philly Manager Dallas Green. "They were as slick as ice. I'm protesting it to the league office. It was a disgrace. Nobody rubbed up the balls. 'Lefty' has to feel the ball to be sharp with his slider."

Pitching icicles isn't easy, but Carlton hung with the task, coaxing the Royals into three double play grounders. The Royals had two men on in each of the first three innings; they got zilch. They had men at the corners with none out and a run in (on Trillo's wild throw) in the sixth; they got nothing more.

Finally, in the seventh, Carlton walked the bases loaded.One Royal finally managed a clutch blow. Amos Otis cracked a two-run double into the left field corner. John Wathan followed with a sacrifice fly. But even Otis had ended two previous two-on innings to help save Carlton's bacon. e

Gura's reluctance for combat was not the Royals' only problem. Frey will have to decide if he was too soft-heart, too sensible, when he took George Brett, suffering from a painful attack of hemorrhoids, out of the game in the sixth after he had two singles and a walk off Carlton. Brett might have been a useful batter in the late innings.

"George was starting to hurt pretty good," said Frey. "I'm not jeopardizing George Brett."

The Phils will only remember the good, like the way they stayed after a razor sharp Gura until they broke through in the fifth with Moreland's single, Maddox's double, Trillo's sacrifice fly and Bowa's single for a 2-0 lead.

"The whole world picked the Royals," Schmidt said with vindication.

"I feel like I'm scratching a 30-year itch," said the 35-year-old Unser, grinning, meaning that he had dreamed of World Series heroics since he was a child.

But for this city, another 30-year-old itch is being scratched. What the Whiz Kids of Shibe Park couldn't do, the Wizard Kids of the Vet may yet accomplish.