Rookie Tim Birtsas pitched a five-hitter and Steve Henderson and Dave Kingman hit two-run homers off old Oakland nemesis Mike Flanagan to give the A's a 10-4 victory today over the Baltimore Orioles.

Henderson and Kingman each homered in the fifth inning off Flanagan (2-3). Flanagan had a career record of 15-4 against the A's and was 10-0 at the Oakland Coliseum before losing today.

The Orioles had only one hit off Birtsas (10-4) before Lee Lacy led off the sixth with his eighth homer of the year. Lacy homered again in the eighth and Floyd Rayford hit a two-run homer, his eighth, with two out in the ninth.

Birtsas struck out five and walked two in his second complete game.

"I wasn't throwing hard, which gave me better control," he said. "As far as being my best game, it was as far as control was concerned because I was in command."

So will he be the American League rookie of the year? "I really haven't thought about that."

Oakland Manager Jackie Moore shrugged off the Orioles' homers.

"Birtsas was keeping runners off the bases," Moore said. "With the big lead, he wanted to make them swing the bat and they have some hitters who can hit it out."

Oakland broke the game open with four runs in the eighth in taking a 10-2 lead. Alfredo Griffin singled home the inning's first run. Mike Davis hit a bases-loaded triple.

Dwayne Murphy drove in Oakland's first run with a single in the second, after Mike Heath's double.

Henderson's homer, following an infield single by Tony Phillips, was his first of the season. Dusty Baker singled before Kingman hit his 26th homer of the year and 403rd of his career. The homer gave Kingman an 11-game hitting streak, the longest of his career.

The A's got a run in the seventh on Baker's RBI single off reliever Nate Snell after center fielder John Shelby made a two-base error.

Baltimore Manager Earl Weaver said, "The A's have a lot of good players and they came to life today."