So much for a possible winning streak. So much, too, for first place. $1

The Baltimore Orioles saw both those things slip away tonight when they lost, 10-0, to the California Angels, who backed the five-hit pitching of Ken Forsch with 16 hits off Mike Flanagan (6-4) and Steve Luebber.

It was the sixth loss in seven games for the Orioles, who had won the series' opener Friday night, 6-4. It dropped them out of the American League East lead for the first time since May 18. Baltimore is one game behind the New York Yankees, 2-0 winners over the White Sox, and four percentage points ahead of the Milwaukee Brewers.

The night made Manager Earl Weaver seem rather prophetic. "Even with the losing streak we're still in first place," he had said after Friday night's triumph. "But sooner or later you have to win some games.We have to win again tomorrow or we won't be there."

Baltimore did not even come close, thanks to Forsch's masterful pitching and Flanagan's continued problems against this AL West club. In pitching his league-high fourth shutout and getting his eighth win in 11 decisions, Forsch never allowed more than one hit an inning and only one runner got past second base. That was catcher Rick Dempsey, who broke a 0-for-24 slump with an eighth-inning double and took third on an infield out.

The Angels got home runs from Don Baylor and Bobby Grich in the second, got four more off Flanagan in the fifth, and had decided the issue long before Dan Ford touched Lueber for a three-run homer in the eighth.

It was not a completely enjoyable night for California, however, because it lost Grich for the next four to six weeks. The second baseman was hit by a luebber pitch to force in the fourth run in that fifth inning and suffered a fracture for the fifth metacarpyl bone on his left hand.

The only infield reserves on the Angel roster are Freddie Patek and Bert Campaneris.

The Orioles had accumulated 14 hits off five California pitchers in Friday night's victory, but they found the going more difficult in their first look at Forsch.

A right-handed sinkerball specialist, Forsch was obtained from the Houston Astros prior to the start of the season. He had snapped a personal two-game losing streak with a three-hit, 3-0 victory over Toronto in his last outing, and he looked just as sharp tonight.

Only 1-2 lifetime against California, the victory coming July 19, 1979, Flanagan got through the first inning unscathed. But he made a couple of mistakes in the second.

He served up a fat 1-1 offering to Baylor, and the Angels' designated hitter deposited it in the leftfield seats for his eighth home run of the year, his second against Baltimore. Then with two outs, Grich jumped on a 1-2 pitch and lined it over the left-field wall. It was his sixth home run, and extended his hitting streak to 13 games.