Alan Jones, newly crowned world's road racing champion, survived a first-lap off-course trip to win the 22nd United States Grand Prix today, setting one-lap and race records along the way.

The 33-year-old Australian already had clinched the driving title going into today's race. Still, he cruised home a four-second winner over his teammate on the Williams-Ford team, Carlos Reutemann, with Didier Pironi, Ligier-Ford, third, 12 seconds behind.

Only one other finisher, Elio DeAngelis, Lotus-Ford, was on the same lap with the leading trio. Fifth was Jacques Laffite, in a Ligier, with Mario Andretti, the 1978 world champion, scoring his first Grand Prix point of the year by finishing sixth.

In spite of what he said was a "bumpy" track surface, Jones smashed Reutemann's 6-year-old race record by completing the 199 miles over the Glen's 3.3-mile circuit at 126.37 miles per hour. The old record was 119.12 mph. The winner's fastest single lap of 129.2 miles per hour broke Jean-Pierre Jarier's mark of 122 set two years ago.

The champion started in fifth place as fastest qualifier Bruno Giacomelli in an Alfa Romeo led the 24-car field off from a standing start. Going into the first sharp right-hand turn a half mile from the start, Jones and three other cars crowded into the corner.

"I went too deep into the corner, locked up the rear wheels and went off," said Jones. "But I kept my skirt clean." He was referring to the undamaged skirt around the bottom of his machine. This shield creates a suction under the car holding it to the track and permitting top speed into turns. Without the skirt, Jones would have had no chance.

When he recovered, he was in 13th place as Giacomelli, seeking his first Grand Prix win, motored off to a four-second lead over Nelson Piquet, Brabham-Ford, with Reutemann third. The rest of the field was well behind the leaders after only 25 miles.

Giacomelli had a five-second lead at 50 miles with Jones now in sixth place, 18 seconds behind him. Twenty miles later Jones was in fourth.

Piquet's bid ended at 72 miles when he spun off the track at the first turn.

He was uninjured. Giacomelli now had a 10-second lead over Reutemann with Pironi in third being pressed by Jones. In another two laps, he had been passed by the new champion. Two laps later, Reutemann yielded second to Jones, who still trailed, now by 13 seconds.

It was over for Giacomelli just after the halfway mark. He stopped on the course when an electric cable came loose and his car lost all power. With 98 miles to go, Jones finally had the lead with Reutemann two lengths behind him.

"I was determined not to relax. I wanted to get out, enjoy myself and have a good old go," said Jones. "I had nothing to lose and I wanted to try for a new lap record."

Jones then built a four-second lead over his teammate with Pironi, who had never been worse than fourth the entire race, now in third. There were no changes the last 75 miles of the race as Jones got his lap record with 45 miles to go.

Race day was cold but clear for a disappointing crowd estimated to be about 50,000. The uncertainty over whether the track would be approved for the race was regarded the major factor in the small turnout.

There still is no formal agreement the Grand Prix will return here next year. The track needs additional repaving and the chilly October weather finds favor only with some of the elegant ladies traveling with the Grand Prix teams. "It gives us a chance to show off our furs," said Marie-Helena Fittipaldi, wife of two-time world champion Emerson Fittipaldi.