Once can be whistling in the dark. Twice, and it's time to pay attention.

The rumblings that began in Memorial Stadium on Saturday night turned into a roar this afternoon. For the second time in 20 hours, the come-from-behind, deep-depth Baltimore Orioles gave themselves the baseball equivalent of a resuscitating electric shock to the heart.

The Oriole bench finally seems free from bondage, as the Oakland A's learned to their chagrin today when Lenn Sakata and Jose Morales drove in six runs in the seventh inning of an 8-4 Baltimore victory.

Before Morales and Sakata arrived, the Orioles trailed, 4-2, in the sort of slow, sloppy, nationally televised game that has helped make pro football the national pastime.

After they had finished their bases-loaded work -- Morales hitting a two-run double and Sakata getting the first grand slam of his life -- the crowd of 15,581 had gone from grumpy boredom to standing-ovation delight.

Those two clutch swings made a winner of Dennis Martinez (11-4), who is tied for the AL lead in wins and sniffing a Cy Young candidacy. Martinez labored through a 148-pitch 12-hitter just three days after working 10 innings.

"This could turn our whole season," said Martinez.

The Oriole rally, which improved their record to 15-11 and ended an 0-6 jinx in Sunday home games this season, also sawed the goat horns off the head of Ken Singleton, whose two miserable plays on catchable flies to right field made all four Oakland runs a gift.

The climax of this 199-minute Oakland stallathon came suddenly and unexpectedly with two out and none on in the seventh. Oakland relief ace Jeff Jones, who had struck out five, carelessly walked both Singleton and Eddie Murray. On came Bob Owchinko to complete the horrid bullpen hat trick of walking the bases loaded by passing Bennie Ayala.

Billy Martin, managing in street clothes from the clubhouse while serving a suspension, called in rookie fireballer Dave Beard, presumably to face the logical Baltimore lefty -- Jim Dwyer.

But Earl Weaver played a hunch. He knew Morales was smoldering with anger after taking three straight strikes with the bases loaded in the bottom of the ninth of a tie game on Friday. Always let an angry man hit.

Morales was swinging as soon as he left the on-deck circle. On the first pitch, the same jamming fast ball that had frozen him on Friday, Morales crunched a liner past third, a foot fair, to tie the game, 4-4.

The next Beard pitch drilled Doug DeCinces in the back to reload the bases.

Again, the percentages said to go with Dwyer. Again, Weaver had a hunch, especially after seeing Sakata smoke six hard singles in 12 at bats in this series. As Weaver jogged out to sympathize with DeCinces, he jabbed his finger in Sakata's chest in the on-deck circle and yelled, "It's you . . . you."

As Weaver jogged back, he recalls, "Lennie still didn't look like he believed me, so I yelled at him again, 'It's you.' "

All Weaver was hoping for was that a wild rookie would walk a 5-foot-7 batter. Weaver even gave Sakata the take sign on the first three pitches. Finally, he let the little utility man hack.

"Jeez, I shoulda let him swing earlier," chuckled Weaver after seeing the rising 400-foot liner clear the left field fence.

"That's the first grand slam I've ever hit anywhere, even Little League," bubbled Sakata. "Remember, I don't even hit 'em out in batting practice."

In many ways, Morales and Sakata represent the simmering aggravations that have bedeviled the talented Oriole bench all season.

"When I came to bat, I was angry. When I don't come through in the clutch, it gets inside me," said the 36-year-old Morales, whose 99 career pinch hits are seventh-best in history. "I have never been a loser. I picked this team (as a free agent) because I wanted a winner."

This Monday, Morales, whose .294 career batting average is the highest on the Orioles, paid his largest dividend with a three-run game-winning homer on his first pitch in the 11th inning in Seattle.

"Jose gets up in the morning and he starts talking about hitting," says Coach Ray Miller, at whose house Morales is temporarily living during the second season. "By the time he gets to the park, he's already convinced himself that he's three for four."

For Sakata, 28, the pressures of being a utility man are greater than on Morales, who long ago accepted his special role. Sakata has become a fanatical weightlifter, and, according to Dan Graham, "can bench press 350 pounds."

"It eats at Lennie not to play," said Miller. "Before every game, you can hear him in the weight room slammin' that steel, getting out his frustrations."

This weekend, Sakata, who has torn up every level of minor league pitching, but has a .194 big league career average, looked more than adequate at short. And his muscleman hitting has Weaver all excited. "Sakata's got as much range as Robin Yount or Roy Smalley," said Weaver, citing two offense-first shortstops. "As long as he keeps hittin' like this, he stays at short."

As long as the Orioles play like this, Weaver and his flock can breathe sighs of relief while listening to the almost forgotten sounds of the Baltimore bench's bats.