Ken Singleton's run-scoring double on the right field foul line with two out in the ninth inning capped off the Orioles' furious late-inning rally tonight and boosted Baltimore to an un believeable 8-7 come-from-behind victory over the shocked Oakland A's in a game the Orioles had no business winning.

The thriller before almost 25,000 frenzied Memorial Stadium fans kept the Birds 2 1/2 games behind New York, which won in extra innings.

It looked for sure that the A's had finally put away the Orioles for the second straight night after scoring single runs in the eighth and ninth innings.

Trailing, 6-2, with two out in the eighth, Benny Ayala hit a three-run pinch hit home run deep into the left field bleachers, scoring Al Bumbrey, who had walked, and Rich Dauer, who had doubled, cutting the Oriole deficit to 6-5.

Entering the ninth down, 7-5, the Orioles resumed their fierce attack as Doug DeCinces led off with a single, followed by a walk to pinch hitter John Lowenstein. With one out Bumbrey hit what should have been a game-ending double play ground ball, but second baseman Mike Edwards let the ball roll between his legs, scoring DeCines and again cutting the Oakland lead to a single run.

Dauer followed with an RBI sacrifice fly to left field and Lowenstein crossed the plate with the tying score. That set the stage for Singleton -- tonight's hero and spoiler -- who lashed a Jeff Jones fast ball down the right field line to score Bumbrey with the winning run, setting off a wild celebration.

Singleton's forth inning home run -- his 21st and fourth of this nine-game home stand -- to center field was the only Baltimore hit off Mike Norris (18-8), who pitched seven brilliant innings tonight before leaving the game because he was tiring after throwing 113 pitches in the intense humidity.

Norris, who entered the game with the American League's second-lowest earned run average (2.34), retired the first 10 Baltimore hitters before third baseman Dave McKay's throwing error ended Norris' perfect game. Singleton, the next batter, unloaded on a hanging curve ball for the first Baltimore hit.

Oakland had nicked Baltimore starter Scott McGregor for three runs in the first inning on hits by Rickey Henderson, Dwayne Murphy and Mike Heath, sandwiched around Tony Armas' RBI fielder's choice. Tim Stoddard (4-3) gained the win in relief of McGregor, who pitched a mediocre 7 2/3 innings.

While the Orioles cheered the replay of Singleton's double in the clubhouse -- his 17th game-winning RBI -- a somber Norris sat in the Oakland locker room explaining why he wasn't bitter about losing a game which he left with a one-hitter. "I can't point a finger at anyone," said the 25-year-old righthander with 19 complete game in 28 starts. "If anyone get the blame, I do for admitting to Art Fowler (A's pitching coach) that I was tired. It's not Billy Martin's fault, so don't blame him for taking me out. He figured I'd be more honest with Art on whether or not I was tired that's why he sent him to talk to me between innings.

The Orioles committed two errors and had five hits in their second less-than-championship caliber performance against the A's and their league-leading pitching staff (3.5 ERA)."

We've played terribly the last two nights," said Dauer. "Maybe this comeback win will help us snap out of it and put together a winning streak."

While Dauer talked, Eddie Murray and Mike Flanagan just danced around the clubhouse to a loud disco beat as the lyrics told the story of Baltimore's spirited victory: "Baby we can do it . . . take our time . . . do it right . . . We can do it baby . . . Do it tonight."