They were the last three losses before Manager Tom Lasorda got the winning streak he had sought for weeks. They were the three losses that prefaced the Los Angeles Dodgers' rapid rise back to first place.

On Aug. 10 in Cincinnati, the Dodgers continued the 7 1/2-week burst of bad baseball that had more than wiped out their 5 1/2-game lead in the National League West. They lost to the Reds that night, 9-2, and fell 6 1/2 games behind first-place Atlanta.

The defeat drained the last ounces of patience from Lasorda. After the game, he overheated in a clubhouse meeting. Then veteran Rick Monday convened a players-only meeting.

The meetings replaced midseason lethargy with pennant-race urgency. But there was still no more of a race three nights later, when Atlanta's Bob Watson hit a two-run homer in the bottom of the ninth to beat the Dodgers, 8-7, and keep them 6 1/2 out.

Watson said he hoped his homer would crush the Dodgers. Instead, it seemed to solidify them. They won the next day to get within 5 1/2 of Atlanta.

The Dodgers went home and lost the next night, 7-3, to San Francisco as Burt Hooton's winless streak grew to seven starts.

But the most significant moment of the NL West season occurred that night in Atlanta as the Braves were losing. Atlanta cleanup hitter Bob Horner broke his wrist and was done for the season.

The next night the Dodgers began an eight-game winning streak. They lost in Philadelphia, then won four more in a row to reach first place, completing the streak and the takeover with a doubleheader sweep Monday night in New York.

"Who would have thought we'd be in first place?" asked right fielder Mike Marshall.

Lasorda bubbled like champagne. "It's great to know that we could come so far back in such a short time," he said. "It's a tremendous achievement. We did it by playing determined, aggressive baseball."

His generalizations would not have been possible without such specifics as the Cincinnati meetings and the Horner injury.

Atlanta without Horner is an unplugged neon sign. Going into this weekend, the Braves were 5-10 without him and had been shut out as many times, three, as they had been all season previously. Also, Phil Niekro was their only starter with more than one victory since July.

Not surprisingly, there was one key game-to-game element in the Dodgers' ascent: quality pitching. The Dodgers, more than any other team, have for years made sure they have enough pitching. And in the 12-1 streak, they did not give up more than three runs in any victory.

Not coincidentally, the Dodgers' defense--leading the league in errors as of mid-August--suddenly improved. The hitting was no more plentiful. It just had a chance to be more timely, thanks to the pitching.

Jerry Reuss, winless since May, won three times in the 12-1 burst. Rick Honeycutt, acquired from Texas for pitcher Dave Stewart two weeks ago, replaced Hooton in the rotation and dominated the Phillies in his first two starts. Bob Welch beat the Mets twice, the second time with a chip fracture in his pitching wrist that he says will not sideline him. Alejandro Pena continued to look like a young Mario Soto.

The only problem, surprisingly, was Fernando Valenzuela. He was leading the staff in victories with 13, but at the end of August was only 5-6 since mid-June, had the highest earned-run average among the starters and was without his 1981-82 sharpness.

Despite that, Mets Manager Frank Howard said, "The Dodgers have one outstanding staff. But it's going down to the last week. Atlanta is going to get hot again. Both teams are a tough piece of work."