LaMarr Hoyt limited the Orioles to six hits as he became the major leagues' first 15-game winner, and his Chicago White Sox scored two unearned runs in the fifth inning tonight to beat Baltimore, 2-1. It was the Orioles' seventh straight loss.

The Orioles began the series with the White Sox, who have won six of seven, in first place but have dropped to fourth in the tight American League East, one game behind first-place Detroit.

The losing streak equaled the longest by the Orioles this season. Manager Joe Altobelli was ejected for arguing with plate umpire Ted Hendry in the eighth inning. He closed his clubhouse immediately after the game.

Hoyt (15-10) tied a career high by striking out nine. He walked three in pitching his sixth complete game of the season. He has won four straight.

"But I have more losses than I should right now," he said. "I'm not saying I could have won 20 or anything by now, but there are some games I should have won but didn't."

The Orioles' only run came in the fifth. John Lowenstein led off with a walk and scored on Ken Singleton's double that barely eluded left fielder Ron Kittle.

"I was in complete command and felt I should have had a shutout," said Hoyt. "But let that slide."He added, "It's the best game I've had in a long, long time. My ball was moving real well in and out and the hitters couldn't sit on it. I felt like I was throwing the cover off the ball."

Mike Flanagan (6-2) was the loser, his second defeat by Chicago in six days. "He pitched a very strong game. His curve ball was really working," said a sympathetic Tony LaRussa, Chicago's manager.

The White Sox, who lead the AL West by 6 1/2 games over Kansas City, came back with two runs in their half of the fifth.

Vance Law led off with a walk and Scott Fletcher singled to right. Third baseman Todd Cruz was given an error when he dropped catcher Joe Nolan's throw on Julio Cruz's sacrifice attempt to load the bases.

Dave Stegman, called up from the minors Thursday, then hit a sacrifice fly to right to score Law. Carlton Fisk followed with a sacrifice fly to left, scoring Fletcher.