Chet Lemon's three-run home run in the eighth inning, his second homer of the evening, ruined Jim Palmer's attempt at survival by guile tonight as the Detroit Tigers defeated the Baltimore Orioles, 9-3, before 40,510 at Memorial Stadium.

Consequently, the Orioles, who had been in first place in the American League East for 49 of this season's 83 days, are tied for first with the Tigers and the Toronto Blue Jays, who lost, 5-2, to Seattle. The Orioles, Tigers and Blue Jays have 39-30 records.

On a soft summer evening made for poetry, Palmer and the Orioles performed a splendid version of comeback baseball against Detroit, a team busting through a nitroglycerine-like 17-7 June.

Trailing, 4-0, the slumping Orioles scored three in the fifth off starter Dave Rozema, the southpaw-like right-hander who, according to Tiger lore, once washed his car with Brillo pads.

The comeback was accompanied by a resurgence by Palmer (2-2), who held Detroit scoreless in the fourth through seventh innings, holding the 4-3 score intact.

In the eighth, though, Palmer lost his spell: Lance Parrish opened with a single, his third hit of the game. One out later, he went to third when Glenn Wilson drove a hit-and-run grounder between Palmer's legs into center.

Then came Lemon, who duplicated his two-run homer in the second inning with a three-run shot (No. 11 for the year) about 10 rows deep into the left field bleachers, providing a shuttle service to the 4-3 lead. Now it was 7-3.

Two batters later, Palmer was gone. One inning later, Larry Herndon hit a two-run homer (his sixth) off reliever Tippy Martinez. The Orioles, who have lost three in a row and six of eight, had given up nine runs for the second straight losing night.

After the Orioles' feathers had fallen to earth, Detroit Manager Sparky Anderson was saying things like, "I don't get high and mighty about winning. It's a long season." And, "We have the best second baseman (Lou Whitaker), shortstop (the injured Alan Trammell) and catcher (Parrish) in baseball."

Then he stated the obvious: "Lemon is hot."

Orioles Manager Joe Altobelli, who had relievers warm up three times during Palmer's ebb-flow-ebb effort, said he didn't replace Palmer in the pre-Lemon eighth for a good reason:

"I could see Lemon hitting a ground ball-double play," said Altobelli. "Sure, any time you see a three-run homer you're shocked."

Palmer's explanation of his 125-pitch game? He didn't have one. By game's end, his locker room cubicle was empty.

Meanwhile, the Orioles' bats continue to lie in state. The Orioles are hitting only .221 in this 2-5 home stand. They had only eight hits tonight.

"We're too good a team to be hitting like this," said outfielder Gary Roenicke. "We're not scoring. We're not getting good pitching. With that combination, you won't do too well."

Detroit took a 3-0 lead in the second after Wilson's sacrifice fly and Lemon's two-run homer. In the third, the Tigers made it 4-0 when leadoff hitter Whitaker walked, advanced two bases on consecutive ground outs and scored on Parrish's ground single to left.

The Orioles finally broke through in the fifth. Lenn Sakata opened with a ground double that bounced off the wall that juts out down the left field line. One out later, Aurelio Rodriguez fought off a 3-2 pitch for a run-scoring single to center.

After Al Bumbry forced Rodriguez at second, Roenicke doubled to left center, scoring Bumbry to make it 4-2. Then Cal Ripken Jr. singled to right, scoring Roenicke.

One single by Eddie Murray up the middle later and Rozema was gone. He was replaced by Doug Bair (2-1, 1-0 in the AL), who struck out John Lowenstein to end the inning. Bair, recently acquired from the St. Louis Cardinals for the ever-popular player to be named later, pitched the middle 2 1/3 innings and was credited with the victory.