South African Jody Scheckter, a gambler at heart, drove his Walter Wolf Ford today with the skill and confidence one would like to have at Monte Carlo.

With a crowd of a quarter of a million people watching under gray skies that whispered threats but released only a few scattered raindrops, he won the Grand Prix of Monaco for the first time and increased his lead in this year's world championship standings.

Scheckter moved in front of Northern Ireland's John Watson in a bold start and dominated for most of the 76 laps of Monte Carlo's narrow, twisting, celebrated 2.058-mile circuit.

Scheckter led second-place finisher Niki Lauda of Austria, whose Ferrari was the favorite of the vocal Italian contingent that adds spirit to the enthusiastic and knowledgeable Monte Carlo crowd, by between seven and 15 seconds for most of the last 22 laps. But he was concerned about a fuel problem in the closing minutes of the race.

Scheckter crossed the finish line, across from the red velvet-draped royal box, in 1 hour 57 minutes, 52.77 seconds, an average speed of 80.004 miles per hour. He also had the fastest lap, his 35th, 1:31.07.

Lauda, who won here in 1975-76 and was trying to duplicate the feat of three consecutive victories achieved only by five-time winner Graham Hill in 1963-64-65, finished just under a second behind Scheckster at 1:57:53.66. He was driving with painfully bruised ribs, an aggravation of a fracture he suffered last year, strapped.

Lauda's Ferrai teammate, Carlos Reutemann of Argentina, was third, 28 seconds back, allowing Team Ferrari to pad its lead over Wolf, Lotus, McLaren and Brabham in the world constructors championship.

Jochen Mass of Germany, in a McLaren, finished fourth, just ahead of American Mario Andretti, who nudged the guard rail at the Ste. Devote turn in the last of several futile attempts to sneak past Mass on the maddeningly tight circuit.

Ste. Devote is the protectress of this charming little principality built on a picturesquely terraced hill overlooking the Mediterranean. She looked with favor on the 35th renewal of this most elegant of Grand Eprouves the 17 races that decide the world championship for drivers and Formula One constructors.

Cranes perched ready to snatch cars that crash off the road, and the helicopters and frogman-laden boats that patrol the barbor where Alberto Ascari plunged in 1955 and Paul Hawkins a decade later, served as reminders that the men who drive at Monaco live dangerously. But there were no accidents.

Showers also held off after a few sprinkles brought about a sprounting of umbrellas with 20 laps to go. If the streets had gotten wet, Scheckter and the other leaders would have been faced with the agonizing decision whether to sacrifice precious time to get rain tires or to stick it out with smooth ones.

Twelve of the 20 starters finished the race. The Brabhams driven by Watson and Hans Stuck of Germany repeated their recent history of failing in the race after being fast and formidable in practice.

Watson, who earned the pole position for the first time in his grand prix career in the waning minutes of Saturday's final practice, retired at Ste. Devote on the 49th lap with a gear box malfunction. He was saluted by spectators who applauded him as he walked back the pit road.

Stuck, who had the fastest lap in the first practice session, went out after 19 laps with a blown oil pump that started a small fire.

The most spectacular retiree was world champion James Hunt of England, who was spewing a yellow tail of oil and smoke as he pulled up at the guard rail on the rise between the start-finish line and Ste. Devote, the first turn of the demanding circuit through the streets of the city. He had blown the engine of his McLaren as he started his 25th lap.

Scheckter's victory was the 100th in Grand Prix racing for the 10-year-old Ford Cosworth V-8 engine, which is due to be replaced soon by a new, lighter magnesium model, in response to the challenge of the 12-cylinder engines used by Ferrai, Brabham and Ligier.

After receiving the winner's laurel wreath and trophy from Princess Grace along with a royal Peck on the cheek, Schecter recounted the fuel pickup problem that caused him anxiety in the final laps.

There was a petrol (gasoline) surge and I knew something was going wrong and I had to be careful," he said. "The fuel was surging and I was using fourth (gear) instead of fifth and third instead of fourth.

Once considered impetuous, even foolhardy, bu some of his colleagues, possessed of more daring than good judgment, Scheckter has matured and should have a good chance to capture his first world championship at age 27. He finished third last year's standings, as he did in 1974, when he was second at Monaco.

Scheckter, who collected nine points today, has led the driver standings since winning the year's first grand prix in Argentian. That raised the astonishing prospect, now enhanced, of Wolf, the only individual in the coporate world of Formula One team ownership, winning the title in his first year. The next event is the Grand Prix of Belgium at Zolder June 5.

Scheckter, disturbed at losing the pole to Watson about 59 minutes into the 11th hour, seized the advantage back with what he called "a terrific start."

He shared the front row of the grid with Watson, vitally important because the circuit, which was undergone relatively few changes since it was designed by an influential and civic-minded automobile freak named Anthony Noghes in 1929, affords seprecious few places to pass.

Scheckter darted to the lead at the start but Watson, whose only grand prix victory came at Austria last year, waged a tight dual in the early laps.

Watson was only one second behind Scheckter after 34 laps, but he gave up second place to Lauda on the 45th after having to take the escape road at the Chicane, scene of some of Monaco's most horrifying crashes. Graham Hill took the escape road early in the 1965 race and still won. Not so for Watson.

Thereafter Scheckter was never really challenged and could afford to slow up the final few yards. Lauda couldn't get close enough to incite the Italians who blanketed the hill across the harbor, on the far side of the circuit, waving Italian flags and cheering for Ferrari.

Scheckter's time was almost two minutes faster than Lauda's 1:59:51.47 last year, the first at the present distance after slight alterations on the circuit after the 1975 race.

Scheckter has now won six of the 57 grand prix races he has driven since debuting at Watkins Glen, N.Y., in 1972.

As befits the winner of such a legendary race, Scheckter praised the slow, tricky Monaco circuit, archaic but revered and filled with character as it requires more than 1,200 shifts and allows use of only five of the six gears in the boxes of most modern Formula One cars. It is "a fantastic course," he said.

Said Andretti, who had hoped to become the first American winner at Monte Carlo but knew his chances were minimal after he earned only the 10th position on the starting grid with his disappointing practice time. "I was just happy to pick up points." He had won the U.S. Grand Prix-West at Long Beach, Calif., and the Spanish Grand Prix back to back. He got two points here in the 9-6-4-3-2-1 breakdown, and noted "For my car, this is the most difficult circuit." He referred to his many fruitless assaults on Mass. "On the last I hit the guard rail. The circuit is too narrow and the car too wide.

"Hats off to the Wolf team. They really put their act together," concluded Andretti. "They'll be a good target to shoot at."