BALTIMORE, AUG. 18 -- The Baltimore Orioles paid homage to one of their pitching legends tonight, then hoped to watch the groundwork for another continue to be laid.

For five innings, Ben McDonald did his part, but the Oakland Athletics finally solved the precocious rookie and the Orioles provided little support in a 3-1 defeat before a season-best crowd of 49,417 in sold-out Memorial Stadium.

McDonald's first major league loss, ending his remarkable string of five victories in his first five starts, probably was an undeserved one. He struggled for most of the night to control his curveball but carried a 1-0 lead into the sixth inning nevertheless. An evening that began with a ceremony honoring new Hall-of-Famer Jim Palmer looked as if it might conclude with McDonald stealing the spotlight.

But he surrendered the tying run on an Oakland rally in the sixth that began with an infield hit, and Rickey Henderson picked on a hanging curve in the seventh for a two-run home run -- the first homer McDonald has allowed this year.

Next inning, the Orioles lost reliever Mark Williamson with a broken finger.

Henderson's 22nd homer came as he tried to produce a fly ball with Walt Weiss, who had doubled to lead off the inning, at third base. "I was just trying to get the run in," he said. "I got a bonus out of it."

Henderson was making his first start in left field since straining a hamstring against the Orioles in Oakland 11 days ago that caused him to miss McDonald's victory over the A's the next day. He's making up for lost time quickly, with three hits and three RBI in two games here, plus his 50th stolen base of the season tonight -- giving him 10 years of 50 or more steals, two fewer than record-holder Lou Brock.

"It was a bad pitch to Rickey, up in his eyes," said McDonald, who yielded a homer to George Brett this summer that was nullified by a rainout. "He's one of the toughest hitters to face because he's so patient up there and he hurts you so many ways. . . . It was tough for me. I didn't have my best stuff, but I battled."

McDonald (5-1) left after the seventh, having allowed seven hits and three runs -- equaling the most he has yielded in any of his six starts. The Orioles provided meek backing in dropping their fourth straight game and ninth in 12.

A's starter Curt Young, in just his second appearance in three weeks, limited Baltimore to four hits and one run -- on Bob Melvin's second-inning home run -- in 5 2/3 innings. Gene Nelson (3-2) and Dennis Eckersley followed with flawless relief, Eckersley working the ninth for his 38th save in 39 opportunities.

Baltimore, which has scored five runs in its last 41 innings and hit .179 over its past five games, fell to 56-62 but kept seven games behind the Boston Red Sox in the American League East. The AL West-leading A's won for the eighth time in nine games and 13th in 16 to improve to a season-high 34 games over .500, at 77-43.

Even in defeat, McDonald drew much praise.

"To beat this team 1-0, you'd almost have to pitch a perfect ballgame," Orioles Manager Frank Robinson said. "There was not a darn thing wrong with the way he pitched tonight."

Said Oakland Manager Tony La Russa: "I don't really feel like we beat Ben McDonald."

It was a frustrating day for the Orioles on all fronts. Their top winner, Dave Johnson, went on this disabled list this afternoon and Williamson left in the eighth inning clutching the ring finger on his right hand, injured when he lost his balance on the mound. X-rays revealed a fracture, and the Orioles recalled Jose Bautista from Class AAA Rochester; Williamson is expected to miss three to four weeks.

Robinson gave his club a pregame speech that wavered between admonishment for the Orioles' recent doldrums and encouragement for the season's final 6 1/2 weeks. "It was more or less a reminder of what we still can accomplish," he said.

Then McDonald resumed his attempt to show the way to success. And for a time it appeared his magical run wouldn't be halted.

The Orioles grabbed a 1-0 lead in the second on Melvin's fourth homer. The catcher entered tonight batting .133 at home, but he clubbed a high fastball from Young into the left field bleachers just inside the foul pole.

Young escaped a fourth-inning jam created by third baseman Carney Lansford's error by getting Melvin to ground for the third out. He wriggled free of another predicament in the fifth, when Chris Hoiles led off with a single and was sacrificed to second only to be stranded.

Meanwhile McDonald was plugging along. His fastball had its usual pop, but he lacked after the third inning the command of his curve that marked his 8 2/3-inning, four-hit effort at Seattle his last start. He threw one change-up all night.

He faced a two-on, two-out situation in the second but retired Weiss on a weak fly to left. The A's had Henderson on third and Lansford at first with one out in the third, but McDonald struck out Dave Henderson on an overpowering fastball at the knees and got Mark McGwire on a popout.

Oakland tied at 1 in the sixth with a run that illuminated how badly the Orioles miss second baseman Bill Ripken, on the DL with a stress fracture in a foot. Dave Henderson led off with a grounder up the middle that Tim Hulett grabbed but couldn't turn into an out. It was a difficult play, but the kind defensive whiz Ripken makes.

McGwire's single sent Henderson to third, and he scored on Jose Canseco's forceout grounder. Then Rickey Henderson went to work.

"It's frustrating, but what can you do?" Robinson asked. "You can't will hitters to hit, and you can't will pitchers to pitch."