In a sense, the Baltimore Orioles' great chase of 1980 ended tonight by the Bay when Gary Roenicke's solo home run with two outs in the ninth inning broke up a tie and brought the Birds a 3-2 win over the A's and pulled them within a half-game of the league-leading Yankees.

Whatever happens in the roughly 40 days remaining in this pennant race, it will always be a fact that these O's, who were 11 games behind New York 40 days ago, have now caught the Yankees in the only statistic that players notice: the loss column.

The Birds won an excruciatingly tense duel from Billy Martin's A's while the Yanks were losing, for the 19th time in 37 games to California, 3-4.

After Roenicke's 400-foot blast into the left-field bleachers on a 2-0 pitch off starter and loser Steve McCatty, Oakland roared back with a leadoff triple to right-center by southpaw Mike Davis, who only got to the plate as a pinch hitter for Rob Picciolo because Picciolo had to play shortstop when Mario Guerrero became sick.

The A's were even sicker when brilliant reliever Sammy Steward, who worked four shutout innings, fanned Oraldno Gonzalez and Rickey Henderson before ending the madness with a Dwayne Murphy grounder to second as the jubilant Birds danced.

If one moment is to symbolize this pennant race, it should be speedster Davis dancing off third while Stewart bowed his neck and blew away the A's -- those first two innings strikeouts coming with the O's infield looking down the hitters' throats.

The new, extremely-for-real A's, winners of 31 of 47, showed up tonight with another of their stable of hard-throwing fast ball-spitball youngsters on the hill -- Steve McCatty, who despite a 1.82 ERA in his last six starts is only the tough Martin band's fourth-best starter.

The O's scored first in the second as Terry Crowley doubled to the 375-foot sign in left, took third on a Doug DeCinces single and scored on a two-strike Gary Roenicke sacrifice fly poked to right. DeCinces took second on the throw home (alertly), but didn't tag and take third on Rick Dempsey's vicious line out to the track in left. That cost a run as Mark Belanger's single to right only moved DeCinces to third and Al Bumbry flied out.

Jim Palmer (13-9), who surprisingly still has an outside chance for 20 wins in a snakebitten year when he has had little offensive support, got out of the first and third when Dwayne Murphy grounded into double plays after unknown star Ricky Henderson (.303, 81 walks, 62 steals) and walked and singled.

In between, Palmer was unlucky, suffering an unearned tying run as Wayne Cross beat out a bunt in the second inning to the napping DeCinces, took second on a Dempsey passed ball on a high fast ball, then scored on Jim Essian's sickly, handlehit two-out bloop single. Very cheap run.

The O's continued their generosity-to-a-fault by stranding a leadoff double (Dauer) in the third and single (DeCinces) in the fourth. Singleton's whiff (failing to advance Dauer with none out) may have cost a run, while Dempsey missed a hit-and-run sign getting DeCinces caught stealing in the next inning. Sloppy.

But, in the fifth, the O's went ahead on perhaps the rarest of all Bird phenomena -- the pure speed run. Bumbry beat out a chop to first by inches (ending in a somersault), stole second (by inches), went to third on a grounder to short, then raced home as Jeff Cox bobbled Singleton's sharp groundout directly to him at second base.

The A's tied the score, 2-2, in the fifth on a pair of doubled over the third base bag by Tony Armas and Mario Guerrero. But the inning was really a double Bird blessing in the end. Palmer after a pair of 3-1 pitch two-out walks, got Mitchell Page (.244) on a full-count foul pop out with the sacks loaded with A's.

Weaver lifted the nibbling, struggling Palmer and brought in Sammy Stewart to start the sixth. After his first pitch produced a double, Stewart got Gross, Armas and Guerrero on a weak pop up, strikeout and grounder. After a leadoff dribble hit in the seventh and a sacrifice bunt, Stewart fanned Murphy and Page; the last called strike so infuriated Page that he was ejected.

In the never-ending battle of rulebook nit-picking one-upsmanship between Weaver and Martin, Weaver played the game under protest because Martin did not name his substitute DH before the seventh inning began.