Rick Dempsey hit a grand slam today with one of the longest drives of his life, a 430-foot rocket that landed two-thirds of the way up Memorial Stadium's left field bleachers off Charlie Leibrandt and carried the Baltimore Orioles over the Kansas City Royals, 4-3.

Relievers Brad Havens and Don Aase closed up shop on the victory with three innings of broad-shouldered relief as they poured hard stuff past the world champions in the late going.

With that, the Orioles managed to win two games in a row for the first time in three weeks as they climbed to a humble 14-14.

But that's not what had Manager Earl Weaver bouncing around his office and cackling long after the comeback from a three-run deficit was complete.

"Gutty performance," said Weaver of his winning pitcher, Storm Davis, who allowed 10 hits and a dozen base runners in six storm-tossed innings. "How many innings did he work out of jams? All six, wasn't it? Well, it felt like 12.

"But he kept us in the game. When a team has all those chances, like the Royals did, and you don't let 'em blow the game open, it takes the juice right out of 'em. We had that good feeling on the bench. One swing and we'd be back."

That one swing was Dempsey's in the fifth inning.

The 14-year veteran had hit only one bases-loaded home run in his career, and that was on the road. But this time the table was ideally set for home cooking.

The Orioles, next to last in the American League in runs per game this season (3.8), had summoned but one single and a walk off Leibrandt in the first four innings as the big left-hander turned bats to toothpicks with jamming pitches on the fists.

Juan Beniquez opened the fifth with a hard ground-ball double inches inside third base. He took third as Mike Young's seeing-eye grounder found its way through the hole into left. After the hard luck in which they say they have hit this spring, the Orioles believe such luck is overdue.

Floyd Rayford, in a desperate .163 slump after having the season of his life in 1985, filled the bases with an eight-pitch walk. It was a war of wills as Rayford crowded the plate and Leibrandt poured fastballs and sliders at his belt and knees.

Every pitch was borderline, and the last one, a hard slider on the fists, took Leibrandt's heart as umpire Rocky Roe called ball four.

"Rayford said it was a strike. The umpire said it was a strike . . . he told Rick Dempsey so ," said a disgusted Leibrandt, now 4-1. "The first pitch to Dempsey called a ball was also a strike. Now I'm in a tough situation and I have to throw a good pitch."

Dempsey knew it and salivated.

"Man, ever since I hit a few home runs last year 12 , I'm not getting any good fastballs to hit this season. The word must have gotten around," said Dempsey. "Nothing but nasty breaking balls early in the count, even when I'm batting eighth or ninth."

This time, No. 9 hitter Dempsey got "a fastball right down the middle" -- what the players might call a room service cheeseburger -- and knocked it into the 21st row above the exitway, fair by a dozen yards.

"He swung hard and the ball went a long way," grumped Leibrandt, who finished with a 126-pitch five-hitter and had nothing that even resembled a jam in any other inning.

"Aw, I've hit 'em further. Almost knocked one on the roof in Detroit last year," said Dempsey, who had been hitless his last 10 times up.

The Orioles know that Dempsey can supply the occasional "dinger." They know that Havens, who retired the first five men he faced, three on strikeouts, has the sort of knee-buckling left-handed stuff that once made little Tippy Martinez a tall short man. And they know that the 6-foot-3, 220-pound Aase has, in the last year, been as forceful as any right-handed reliever in Orioles history. In 14 games this season, his ERA is 1.13 with eight saves and a win. Foes are hitting a depressed .154 against him.

"I want to meet the doctor who operated on his elbow. He can work on mine," said Royals star George Brett. "Aase's going to help them plenty because he's all the way back now. And he can bring it."

What was something of a surprise to the Orioles was Davis' grit under fire. Everyone knows this 24-year-old has as good stuff as almost any young pitcher in the game. Everybody knows he's smart, maybe too analytical. And everybody knows he's so totally poised as to be almost devoid of emotion on the mound, even when being hit hard.

But that doesn't answer all the questions -- such as why he hasn't won as many as 15 games in a season and when, if ever, he might emerge, as Weaver said today, "as our next Cy Young winner."

The problem is that Davis' nickname should be Calm, not Storm.

"He's got all the pitches, but he's too passive," said Brett. "When you're on the mound, you have to hate the hitter, hate his mother and father and his whole family. In a pressure spot, you've got to give off the feeling that 'I'm coming after you and you're just out of luck, buddy.' Almost all of the best are like that. You can be a nice person the rest of the day.

"I know Storm's a real religious guy and he just seems to have this 'what will be, will be' attitude. I think you got to take care of yourself out there and make things happen."

This afternoon, Brett didn't see Davis wilt when breaks went against him. Davis raged against his fate and so altered it.

A broken-bat single by Steve Balboni in the second, another hit by Balboni in the fourth and a double off the right field wall in the fifth by Frank White each drove home one Kansas City run. But, as Weaver said, "If we only give 'em up one at a time, we'll win a lot of games."

More important was the way Davis struck out the side with a man on in the second, then picked off Willie Wilson in the third. With two on and none out in the fourth, he slammed the door once more. With the bases loaded and one out in the fifth, Davis struck out Balboni and escaped yet again. As an encore in the sixth, he ignored a man on second with no outs and a man on third with one gone.

"I don't think I've ever won a game like that before," said Davis.

He's probably right. A large slice of the Orioles' future depends on whether or not he remembers how he did it.