The Minnesota Twins scored six runs in the first two innings off Baltimore starter Dennis Martinez tonight and cruised to a 7-4 victory that brought them their first series sweep in 23 years of trying at Memorial Stadium.

Kent Hrbek drove in four runs and Gary Gaetti got three hits to extend his batting streak to 17 games as the Twins lengthened the Orioles' losing streak to six. This was Minnesota's 51st visit here since the Washington Senators were transformed into Twins; the only time Minnesota escaped defeat before was on a one-game stop in 1968.

At least, Baltimore was able to send a Minnesota pitcher to his shower ahead of schedule. After Frank Viola and Bobby Castillo had given the Twins their first complete games of the season Monday and Tuesday, rookie right-hander Ken Schrom lasted only seven-plus innings tonight. Still, it was the longest assignment of his brief major-league career, in which he now owns a 5-0 record.

The Orioles, who left 11 men on the bases, departed immediately afterward for Kansas City. Manager Joe Altobelli will mark his 51st birthday Thursday in a park where Baltimore has been beaten seven straight times.

"I wish we were staying here; this is the place to be if we're going to cash in or crash out," Altobelli said. "But we have to win there, no question. You're going to have a game or two like this every season, but we've had six and that's more than enough."

Altobelli indicated that he has had just about enough of Martinez's problems, that tonight made him the major leagues' first eight-game loser.

"It was an uphill climb," Altobelli said. "We can't afford to give anybody a six-run advantage in the second inning, particularly from a starter like Dennis Martinez. He has to pitch better than that. It's time he started getting his stuff together."

Martinez was fortunate to survive the first inning. The first two batters, Bobby Mitchell and John Castino, singled and doubled.

After Gary Ward grounded out, Hrbek brought both runners home with a broken-bat single to right. Gaetti walked on four pitches, then Randy Bush lofted a high drive that was caught by a leaping Al Bumbry with his glove above the seven-foot fence in center field.

Bumbry's superb catch proved only a temporary reprieve for Martinez. In the second inning, Dave Engle singled, stole second and scored on Mitchell's slicing liner to left.

After walking Castino, Martinez struck out Ward. But Hrbek dropped a 1-2 outside pitch into the left field corner for a two-run double. It was Hrbek's 15th double, tops in the majors.

Don Welchel replaced Martinez and Gaetti hit his first pitch into the left field corner for another double and a 6-0 lead. Although the Twins managed just one more run against Welchel, Dan Morogiello and Tippy Martinez, it hardly mattered, because Baltimore could not hit with men on base.

Eddie Murray was especially snake-bitten, although he managed two hits to break out of a four-for-27 slump. Three other times Murray came up with two out and runners in scoring position and lined one-hop shots directly at infielders who managed to throw him out.

The Orioles filled the bases with none out in the third, but managed only one run on Dan Ford's sacrifice fly, as Murray sent a bases-full drive at second baseman Castillo to end the rally.

A wild throw by third baseman Gaetti handed Baltimore two unearned runs in the seventh, with Ford hustling all the way around from first.

Schrom was replaced by Ron Davis after walking the first two batters in the eighth. Joe Nolan greeted Davis with a run-scoring single, but the fast-balling reliever mowed down the next three.

The remnants of the crowd of 17,791 were given some two-out excitement in the ninth, on successive singles by Murray and John Lowenstein, who earlier had ended a zero-for-24 drought. Ken Singleton flied to center on the first pitch, sending the fans home and bringing Castillo out on the field with a broom.

"Somebody said we hadn't swept in 23 years here," Castillo explained. "I was just 4 years old at the time. So I just went out and swept behind their feet. It's nice when you can win and you can have fun."

The Orioles remember the feeling.