Wayne Gross hit two home runs and Eddie Murray broke a tie with an eighth-inning homer tonight as the Baltimore Orioles defeated the Milwuakee Brewers, 5-3.

Gross pushed the Orioles ahead twice, in the fourth inning with a two-run homer and in the seventh with a bases-empty drive. But it was left to Murray to produce his 19th game-winning run batted in of the year, putting Baltimore ahead for good in the eighth. He hit a 3-0 pitch by reliever Jack Lazorko into the middle rows of the right field bleachers, making it 4-3.

Joe Nolan's sacrifice fly later in the inning ended the scoring.

Sammy Stewart relieved starter and winner Storm Davis entering the ninth to earn the save, his 12th. Davis threw 148 pitches, allowed 10 hits and pitched with a runner on second in all but three of eight innings.

In the eighth, Milwaukee tied the game, 3-3, using an infield single by Robin Yount, a walk to Ben Oglivie and an RBI double by catcher Bill Schroeder. But it could have been much worse for Baltimore. The inning ended with runners on second and third.

"That was a little tough," said Davis, now 13-7 with his first victory since Aug. 6. "In the course of a game, there are key innings. The fifth, when (Jim) Gantner hit into a double play, and the eighth . . . sometimes breaks go your way."

Breaks may not have mattered if Gross had not chased starter Tom Candiotti after 6 1/3 innings. Candiotti allowed only four hits but two were Gross' home runs. Another was a first-inning single by Murray, which extended his hitting streak to 20 games (Murray followed it with his ninth stolen base, tying John Shelby for the team lead).

"He was throwing a lot of off-speed pitches," said Gross, who leads American League third basemen with 19 home runs but was struggling before tonight with a one-for-15 batting slump. "His fast ball was 80 miles per hour. Even an average fast ball is clocked at 87. But that stuff is tough to hit when you're getting it over the plate."

Milwaukee took a 1-0 lead in the third on Dion James' RBI double. Gross answered in the fourth with Rick Dempsey on first base. Candiotti served up a slow curve that Gross sent over the right field fence just above the 360-foot sign.

"I hit that ball perfect," Gross said. "It was a real slow curve . . . The second one was a change-up that I double-clutched on. I hit it high. I thought it was going farther than it did." The ball landed in the second row of the right field bleachers.

That gave the Orioles a 3-2 lead in the seventh and, after Dempsey walked, Candiotti departed. The Brewers had tied the score in the sixth when Yount singled, advanced to second on Cecil Cooper's fly to deep center field, and scored on Oglivie's double to left.

After the Brewers rallied once again to tie, Murray was waiting for fast balls. After Lazorka retired Cal Ripken Jr., who was hitless for the third straight game, Murray got what he wanted. So did the Orioles.

Even while going hitless, Ripken almost started something by walking with two out in the first inning. Murray followed with his hit and steal and John Lowenstein walked on five pitches. When Candiotti went to a 3-2 count on Ken Singleton, the crowd came alive. But Singleton went down swinging on a curve.

The victory made Baltimore's record 27-29 against East Division teams. Since 1969, the Orioles have gone through a season with a losing record within the division just once, 44-46 in 1978.

Two pins were inserted today into Orioles pitcher Scott McGregor's left-hand ring finger, broken Aug. 28. McGregor underwent sugery as an outpatient and the pins were inserted to stabilize a bone chip. They will remain in place for four to six weeks.