BALTIMORE, SEPT. 10 -- The Baltimore Orioles, modest conquerers of the mighty American League West, tonight continued to falter against their less-than-overwhelming AL East brethren.

The East's hardly captivating battle for third place centered on Memorial Stadium tonight. And the Orioles treated it much like their derailed push for the division's top spot a month ago, being held to six hits by Frank Tanana and two relievers en route to an 8-0 loss to the Detroit Tigers before 20,688.

The Tigers accelerated the tailspin of Orioles starter Pete Harnisch, who fell to 10-11 with his eighth loss in his last 11 decisions. The 23-year-old right-hander, who has one win in his last nine starts, seems to be tiring beneath the strain of his team-high 173 2/3 innings. Tonight he withered in the seventh inning and watched the bullpen fail him.

Manager Frank Robinson joked recently about removing Harnisch from the rotation so he can moan that no pitcher lasted on the starting staff all season. But Harnisch's inconsistencies are no cause for laughter any more. Although the Orioles insist it's all part of the learning process, Robinson allowed after the game that Harnisch might be the next starter to exit the rotation -- as a precautionary measure more than anything.

"It's a possibility," Robinson said of moving Harnisch to the bullpen. "I worry about any young pitcher going for a full season like he has. Any time you struggle like that, you lose a little of the edge and a little confidence. . . . He made bad pitches tonight. His pitches were up, and it hurt him."

While the Orioles flailed away unsuccessfully at Tanana's tantalizing offerings, Detroit built a 3-0 lead after four innings and battered Harnisch, Kevin Hickey and Bob Milacki for a five-run seventh. And the Tigers, who began the day leading the major leagues in runs and home runs, did all of that without Cecil Fielder or Alan Trammell in their starting lineup.

Lou Whitaker broke a zero-for-25 slide with a run-scoring single, and a two-run home run off Harnisch in the seventh. Travis Fryman, Mike Heath, Chet Lemon and just-recalled rookie Milt Cuyler each had two of Detroit's 12 hits.

And that was more than enough for Tanana, who registered just his second victory since June 14 -- and his first victory here since 1986 -- by holding the Orioles (63-76) to three singles in seven innings with a nifty 82-pitch (59-strike) effort. Mike Henneman and Jerry Don Gleaton finished with two innings of three-hit relief to complete the second of Detroit's first back-to-back shutouts since 1985.

The defeat was Baltimore's 28th in its last 37 meetings with AL East opponents, leaving the Orioles 21-35 against division foes this year. They've lost 11 consecutive series to East teams, this in a year in which they ended 42-41 versus the AL West. They dropped 3 1/2 games behind the Tigers (68-74) in what they consider a meaningful battle for third.

Detroit grabbed a 1-0 lead in the third on Whitaker's two-out, RBI single. The Tigers increased their advantage to 3-0 with two two-out runs in the fourth on Heath's looping single to right and Cuyler's ground-rule double down the right field line. Their seventh-inning outburst was built around Whitaker's blast, two walks and Lemon's two-run single.

Tanana, meanwhile, was in complete control. The 37-year-old left-hander has had a disheartening season, the kind in which his candid manner has led him to declare "I stunk" on several occasions. A 10-start stretch beginning the first week in June saw him surrender 46 earned runs in 40 1/3 innings and fail to complete six innings seven times. The result was a relegation to the bullpen.

But he has fared well since returning to the rotation late last month, though. His four outings all have resulted in Detroit victories, though he has gotten credit for only two of them.

"It was just a matter tonight of making good pitches, hitting locations and changing speeds," he said. "This was a good ballgame for me. . . . It's been a bad year. I'm just glad to be pitching better."

The Orioles hardly managed a well-hit ball off him. Tanana (7-7) had all five of his strikeouts in the first four frames and didn't permit more than one baserunner in an inning. The Orioles grounded into double plays to erase leadoff singles in the third and fifth, and Bill Ripken was thrown out stealing after brother Cal struck out in the first.

"Finesse pitchers seem to give us consistently more trouble than guys who throw the ball hard," Robinson said.

Orioles Notes: Reliever Gregg Olson's 30th save Sunday made him the youngest pitcher in major league history to register 30 or more saves in a season. Olson, 23, beat Bruce Sutter by nine months. . . . The Orioles signed Roberto Clemente Jr. to a Class AA Hagerstown contract. The 25-year-old son of the late Hall-of-Famer played previously in the Philadelphia and San Diego organizations, hitting .229 in 31 games with the Padres' Class A affiliate, Charleston (S.C.), during his last season of professional baseball four years ago.