OAKLAND, AUG. 9 -- The differences between the Baltimore Orioles and the Oakland Athletics cannot be illustrated better than they were today. The Orioles are opportunistic, overachievers who can't afford to squander opportunities, while the A's are liable to cover for multitudes of sins and innings of deficiencies with a couple of quick outbursts of their imposing abilities.

Baltimore wasted chances and gave away runs here this afternoon, and Oakland struck in a few scattered explosions. The result was a 5-2 A's victory before 28,008 at the Oakland-Alameda County Coliseum that left the Orioles heading for Anaheim after two losses in three games. That was after being outscored by one run and outhitting Oakland in each contest.

Today they rapped eight hits to Oakland's five and threatened repeatedly to dispatch A's starter Mike Moore. But Baltimore left 11 runners on base to offset a mostly effective outing by Dave Johnson, who made a handful of poor pitches but was afflicted by bad fortune -- and A's exploits.

Oakland got two runs in the first inning when three consecutive batters fought off tough, jamming pitches for hits. Then Johnson erred in his calculation of the count during a sixth-inning walk to Jose Canseco, and Dave Henderson made him pay by reaching down to yank a low fastball into the second deck of seats in left field.

"I felt really good," said Johnson, who yielded five hits and five runs over six innings in falling to 11-7. "I was throwing the ball pretty much where I wanted to, but they hit a couple pitches I didn't think they could hit and that was the ballgame."

Johnson said he felt only slight pain from a strained lower back that cut his last start short and moved him back two days in the rotation. His legs didn't cramp as they have done recently. But an upset stomach caused him to throw up shortly after the game.

"I felt a little sick when I got to the bench {following his seventh-inning removal}, but that was probably mental," he said. His lack of support included gaffes by each Orioles outfielder in the first inning, an error by first baseman Sam Horn that cost a run in the second and an offense that repeatedly failed to deliver the well-timed hits necessary to keep pace with the A's.

"We had a chance to win all three of these ballgames," Manager Frank Robinson said. "We had a chance {in Tuesday's 3-2 loss}, and we had a chance today. We just didn't get the big hit when we needed it. . . . When you put as many men on base as we did today, you expect to score more than two runs."

The Orioles fell to 54-56, failing for the sixth time in seven opportunities over the past month to reach .500. They were seeking to secure two winning trips to this ballpark in a single year for the first time since 1979, but instead failed to gain ground on the first-place Red Sox.

Doug Jennings started Oakland's first-inning uprising by slapping a one-out, line-drive single to left field botched briefly by Joe Orsulak, and Canseco followed with a double into the left field corner.

Henderson then produced a high, deep fly ball that right fielder Steve Finley seemed to be running down as he raced backward and toward the alley. But the ball eluded Finley's leaping attempt, and Jennings scored despite center fielder Dave Gallagher's hustling play to corral the carom off the wall and hold Canseco at third while Henderson pulled into second.

Mark McGwire scored Henderson with a sacrifice fly to medium center. Canseco easily beat Gallagher's throw to the plate -- which eluded catcher Bob Melvin as Gallagher was charged with the first of Baltimore's two errors -- for a 2-0 A's lead.

The Orioles cut the deficit with a run in the second. Moore walked Mickey Tettleton with one out, then Craig Worthington one out later. Melvin followed with a run-scoring single to center, the first of his three hits today after a pair of RBI singles Wednesday.

But then the Baltimore offense went dormant. The Orioles left two runners aboard in the second when Jeff McKnight flied out to end the inning, then stranded seven from the fifth to the seventh.

Meanwhile, the A's were making the most of their limited opportunities -- and the Orioles were helping them. A leadoff double by Terry Steinbach in the second became an unearned run when, with two outs, Horn botched Carney Lansford's easy grounder to push Oakland's advantage to 3-1.

Horn, a less-than-accomplished fielder, was at first base today because of Randy Milligan's bruised shoulder and Ron Kittle's slight groin pull. The Orioles had been errorless in 19 of their last 25 games.

It became 5-2 in the sixth on Henderson's homer. Johnson walked Canseco to begin the inning after believing his 3-1 pitch was a 2-2 offering, then watched Henderson deposit a low fastball far over the left field wall for his 19th home run. It was the first homer Johnson had allowed in three starts, but the 24th this season, most in the major leagues. "It wasn't even a strike," he said. "It was about four inches off the ground, and he went down and got it."

From there, Oakland's peerless bullpen shut down the Orioles. Moore (10-10) left after 5 2/3 shaky innings, but Todd Burns, Joe Klink, Gene Nelson and Dennis Eckersley -- who earned his 37th save -- followed with 3 1/3 innings of two-hit relief.