BALTIMORE, AUG. 28 -- Fred Lynn's pinch-hit home run in the ninth inning tonight gave the Baltimore Orioles a 6-5 victory over the California Angels at Memorial Stadium.

The home run came just after a 18-minute rain delay, and ended reliever Chuck Finley's magic against the Orioles. He hadn't given them a run in 17 2/3 innings and tonight had shut them out since the fourth inning.

While Finley (2-6) pitched so well losing, winner Mark Williamson pitched to only one batter, pinch hitter Ruppert Jones in the ninth.

Starter John Habyan handled the Angels well early in the game, and his teammates got him runs in each of the first three innings. He had not started since losing to the White Sox July 7. As a starter, he is 0-3, although in nine relief appearances covering 39 innings, he is 3-0 with one save and a 1.91 ERA.

Tonight, though, he couldn't stand prosperity. The Orioles got a run in the first, two in the second on center fielder Mike Hart's home run, and two in the third on two singles and Ray Knight's double.

Jim Dwyer led off the first with a single to center and took an extra base when Devon White bobbled the ball. Bill Ripken's bunt down the third base line went for a single, sending Dwyer to third, from where he scored on Cal Ripken Jr.'s fly to left field.

Mike Young singled to left with two outs in the home second and Hart, in only his fourth starting role since being recalled from Rochester Aug. 14, homered to left field. It was his second homer this season. He had been two for 11 in five games with the Orioles. He played briefly for the 1984 Minnesota Twins but had never homered before this season.

The Orioles added two more in the third to go up 5-0, with singles by Bill Ripken and Larry Sheets and a two-RBI double to left by Ray Knight.

The five-run lead the Orioles got Habyan lasted into the fifth inning, when the Angels scored twice. He had allowed them nothing since Wally Joyner walked in the first inning. But in the fifth, Doug DeCinces led off with a double and scored on catcher Jack Fimple's single to left. Mark McLemore walked and Brian Downing's single to center brought Fimple home. Habyan struck out Jack Howell. But Habyan left in the sixth, after giving up a leadoff home run to Joyner. The homer went to center field for his 26th this season. Habyan, who threw 78 pitches and gave up four hits and three earned runs, left with a chance to win the game, but reliever Mike Griffin allowed the Angels to tie the game later in the sixth inning. Dick Schofield hit an opposite-field homer after White had singled and taken third on Griffin's error.

In the seventh, with Downing on with a single and Joyner coming to the plate, Orioles Manager Cal Ripken Sr. called in left-hander Jack O'Connor, who got Joyner to fly out to center.

Meanwhile, Finley, who relieved starter Mike Witt at the beginning of the fourth inning, continued to shut down the Orioles. They went down one, two, three in the fifth and sixth innings. In the seventh, Bill Ripken reached first on a pop single behind the pitching mound. Cal Ripken Jr. singled his brother to third. But Eddie Murray grounded to shortstop Schofield, who threw to McLemore to force Ripken Jr.

Lynn didn't start because of a thigh injury and joked that his homer enabled him to circle the bases slowly. He picked on a 3-1 pitch.