An unknown quantity, rookie catcher Dan Graham, stimulated the shaky vital signs of the Baltimore Orioles tonight with a game-tying home run and a game-winning single that subdued the Texas Rangers, 4-2.

The Orioles looked to be following a familiar losing script in the fifth inning when some shoddy fielding put Texas and Ferguson Jenkins ahead, 2-1. But in the sixth, Graham swung at an inside fast ball and sent it far over the right-field wall to tie the game.

In the home eighth, Pat Kelly led off with a single and stole second. The threat looked stillborn when Terry Crowley flied out and reliever Jim Kern fired three fast balls past Ken Singleton. But after Eddie Murray was hit in the leg by a Kern curve, Graham laced a slicing single to score Kelly with the go-ahead run. Center fielder Mickey Rivers misplayed the ball, allowing Murray to score the final run.

Since being called up early this month, Graham has four hits in two games -- two homers and two singles. He was three for four tonight.

"When Kern blew the ball past Singleton I thought to myself, 'Damn, that guy is fast,'" said Graham. "When he got behind me in the count, I was looking for that fast ball. With Kern, there's no doubt what he'll throw."

Before Graham came up, Texas had lefty Sparky Lyle in the bullpen and Oriole Manager Earl Weaver said after the game he would have pinch hit for left-handed batter Graham if Lyle had come in. "Lee May has hit Lyle very well throughout his career," Weaver said.

The moves were not made and the Birds grabbed a direly needed victory.

Another breakthrough was the 8 1/3 innings of strong pitching by Baltimore starter Steve Stone. He won his fourth of seven decisions, tops on the staff, which yet was denied its first complete game since April 26 as Tim Stoddard came in to get the last two outs.

Early in the game, the O's hinted they might revive the magic they had left in cold storage since fall. They jumped ahead in the first on singles by Al Bumbry -- extending his hitting streak to 17 games -- and Kelly and Singleton's sacrifice fly. The Oriole defense also sparkled with a successful pickoff move by Stone in the first inning, a stunning backhanded stop by second baseman Rich Dauer in the second and a slick, leaping catch by centerfielder Bumbry in the third.

Also, in the third though, Oriole malaise resurfaced as Texas catcher Jim Sundberg hit a 310-foot fly toward the 309-foot mark in left. Homerun, tie score.

Problems continued in the fifth when Ranger Pepe Frias hit a two-out roller to third that Doug DeCinces couldn't handle. It was scored a hit to much disdain among the 12,707 fans. Frias moved to second on a wild pitch that Graham seemed to have stopped before falling down. Rivers promptly ripped a ground-rule double to put the O's down, 2-1.

After wasted Baltimore scoring opportunities in the third and fourth innings, Graham brought the home team to life with his sixth-inning homer.

"I know I came here to help out the hitting attack," Graham said. "The team was hitting .210 early in the year. When I got here, Earl said to me, 'You may play today, you may play tomorrow, you may play in 10 days or you may not play the whole year. Just be ready when I need you.'"