The Baltimore Oriole pitching staff, by far the best in the American League this season, took a night off.

Bob Watson hit for the cycle, the first Boston player to do so since Carl Yastrzemski in 1965, and Jim Rice drove in four runs as the Red Sox pounded the Orioles tonight, 10-2, before 49,525 fans.

The loss, in front of the fourth largest regular-season baseball crowd ever at Memorial Stadium, leaves the Orioles' magic number at 5 in their bid for their first American League East Division title since 1974.

The Red Sox scoring barrage ended a remarkable streak for the vaunted Oriole pitching staff. Since Aug. 26, when Mike Flanagan beat the Chicago White Sox, 12-7, in the first game of a doubleheader, Oriole pitchers had gone 20 straight games without giving up more than four runs in a game.

"I don't expect to give up more than three or four runs -- ever," said Ray Miller, Bird pitching coach, who watches over his flock with a fatherly eye. "This is a very solid staff. I'm not overwhelmed by anything it does."

This was a night when the Red Sox temporarily forgot their late-summer miseries and pummeled Oriole starter Dennis Martinez (15-14) and standout relievers Tippy Martinez and Don Stanhouse for 15 hits.

Dennis Martinez dropped his sixth game in his last seven decisions, giving up 10 hits in 6 1/3 innings and staying in constant trouble with bad pitch selection and wild pitches, Stanhouse, the Oriole bullpen ace, gave up his first runs in 14 innings when he allowed Watson's mighty two-run homer in the ninth, Boston's final blow.

"I'm not worried about Dennis," Miller said. "He's pitched great over the last month. We haven't gotten him a lot of runs, and the games we're losing seem to be always when Dennis is pitching."

The Prioles could manage only seven hits off the usually shell-shocked Red Sox pitchers. Starter Steve Renko (10-8) lasted 5 1/3 shaky innings and Dick Drago finished.

The Orioles, who seems to cherish falling behind early, spotted the Red Sox a 2-0 lead in the second.

The runs resulted from Oriole sloppiness, a rare occurrence during this dreamlike 96-50 campaign. After Yastrzemski led off the second inning with a double, Martinez grooved an 0-2 pitch to Watson, who ripped it to right. When Ken Singleton misplayed the ball Yaz scored and Watson took second.

Then Martinez sent a curve ball into the dirt a foot wide of the plate and Watsom moved to third. He scored on Mike O'Berry's sacrifice fly.

The Birds got one run back in the fourth when left fielder Pat Kelly, averaging one RBI in every six at-bats, scored Singleton with a double off the 378-foot sign in right.

Dennis Martinez couldn't survive the seventh.

Rick Burleson, Ted Sizemore and Fred Lynn singled consecutively, Lynn getting his 114th RBI. And after another Martinez wild pitch Rice ripped a two-run single to right center, giving Boston a 5-1 cushion.

The outburst overshadowed Al Bumbry's defensive gem one inning earlier, preventing two Boston runs, Hobson creamed a Martinez offering with Yastrzemski on base, and Bumbry raced to the 385-foot sign in right-center, scaled the fence and made the grab a foot above the fence.

After Bumbry doubled home pinch hitter John Lowenstein in the eighth to raise the hopes of the Orioles fans, old-fashioned Bosox power, the kind usually reserved for Fenway Park, silenced the Birds in the ninth.

Showing disrespect for the Orioles' 3.21 team ERA, the Sox added five runs. With one out, Sizemore reached on an infield hit, Lynn reached on a Billy Smith error, Rice bounced a double over third baseman Doug DeCinces' head for his 117th and 118th RBI, Yastrzemski singled in Rice, and Watson belted a good, low breaking ball into the left field bleachers.