His may be baseball's best story in 1986, partly because he's so admired and partly because, both mentally and physically, he has defied seemingly overwhelming odds.

His name is Dennis Leonard; he is 34, and after three years and four knee operations, his pitching career has been reborn.

How reborn? As the Kansas City Royals pounded the Baltimore Orioles, 11-1, this afternoon before 33,690 at Royals Stadium, he pitched seven shutout innings, allowing three hits, walking one and striking out four.

How reborn? His record is only 3-2, but in five starts he has been baseball's best pitcher, going 37 innings and allowing 26 hits, three earned runs and five walks while compiling a 0.73 ERA.

"This is so much fun," he said. "A lot of people thought I'd never be back here. I always thought I would be, but everything has worked out better than I could have imagined."

He got the 11-12 Orioles on a day when the Royals ripped three pitchers for 17 hits and the Orioles went another game without a home run.

Kansas City left fielder Lonnie Smith returned from the disabled list to go three for three. Center fielder Willie Wilson and shortstop Argenis Salazar also had three hits apiece. Salazar, a career .166 hitter, had five RBI.

Orioles starter Scott McGregor (2-3) pitched himself a little closer to the bullpen, allowing six hits and five runs in 3 1/3 innings, and what followed was a disaster: Reliever Bill Swaggerty, just up from Class AAA Rochester, allowed six hits and two runs in an inning, and Brad Havens allowed five hits and four runs in 3 2/3 innings.

The game was out of hand so quickly -- the Royals led by 3-0 after two innings, 7-0 after five and 11-0 after six -- that Orioles Manager Earl Weaver could only sit in his office after it had ended and wonder when or if his pitching and home run hitters would come around.

"They ought to let the people that paid to see this one come some other time," he said. "The best thing I can say is that Havens showed a lot of heart. It didn't look like we were going to go nine. Outfielder Jim Dwyer was the next pitcher.I don't know what's wrong with McGregor. I really don't, but our pitching is showing all the signs of last year. The team ERA is up to 4.13. I hope we start to turn it around."

This one was over quickly. Smith led off the bottom of the first inning with an infield hit and went to third on Wilson's double. The Royals scored on sacrifice flies by third baseman George Brett and second baseman Frank White. They made it 3-0 in the second on catcher Jim Sundberg's single and Smith's triple.

In the fourth, it went to 5-0 on right fielder Darryl Motley's double, Salazar's RBI single and singles by Smith, Wilson and Brett. Salazar drove in two runs in the fifth with a single and two in the sixth with a double.

Meanwhile, the Orioles were getting almost nothing off Leonard, who allowed two runners to second and one to third in seven innings and retired the last 11.

They did score off Steve Farr in the ninth on a walk to Cal Ripken and singles by Mike Young and designated hitter Larry Sheets.

Leonard's ERA is the best in the major leagues, which isn't bad for a guy who was considered finished on May 21, 1983, when he threw a pitch to Ripken and tore a tendon below his left kneecap.

He is the only three-time 20-game winner the Royals have had, but to get back to the mound, he underwent daily rehabilitation that lasted four hours and more. He didn't even throw from a mound until last July and pitched 21 1/3 innings in the minors at Fort Myers and Memphis last summer before getting in for two major league innings in September.

"I used to fantasize a lot when I was in here working out alone," he said, waving his hand around the Royals' clubhouse. "I had plenty of time to think what might happen, but mostly I was thinking of getting back out there again. If you'd told me I'd throw a three-hit shutout my first time out and have these kinds of stats after five starts, I'd say, 'Who are you kidding?' "

He no longer throws 90 mph, but as Sheets said: "He threw me one pitch 87 mph, another 82, another 83. He throws his fastball a couple of different ways and changes speeds on his breaking pitch. You never seem to get your timing down with him."

If Leonard has started fast, it may be because he had to. The Royals began spring training with one of baseball's best and youngest pitching staffs, and almost no one in their front office thought Leonard had much of a chance.

"Since I had to prove I could still get people out, I had to go to spring training and throw all my pitches," he said. "I couldn't just go down there with the idea of getting ready, like I used to. So the result is that by the time the season started, I had all my pitches. That's been the case. I've had my curveball, slider and a decent enough fastball. I used to think pitching was being able to throw a 90-mph fastball. That may be the most overrated thing there is."

Meanwhile, Weaver was again fretting about his pitching, especially left-handers Mike Flanagan and McGregor, who have failed to complete the fifth inning in five of their 11 starts.

He couldn't dwell on the pitching because there also was hitting to worry about. Young, who hit 28 homers last year, has gone 75 plate appearances without one, and Floyd Rayford, who led the team with a .306 average last season, is down to .189.

"This may be the longest I've gone without a home run," Young said.

Weaver said: "You just hope the opposition hasn't found out something [about getting them out]. I am concerned."