Harold Solomon of Silver Spring, Md., last year's runner-up, was upset in the fourth round of the French Open Tennis championships today by Spanish Davis Cup player Jose Higueras in a performance that one observer described aptly as "like watching air go out a tire."

Solomon led, 4-3, 30-0 on his serve, then went totally flat in each of the first two sets. He displayed his usual sparks and competitiveness only in the third 40-0 in the fourth to lose the tedious 3 1/2 hour match, 4, 7-5, 2-6, 6-3.

"I dno't what happened. I couldn't maintain my concentration. I couldn't maintain anything." Solomon said. "I'm disappointed. I had a good draw and I just played a horrendous match."

Higueras, 24, who fractured his left elbow in a fall on the center court here last year, plays Phil Dent Wesdnesday for a place in the semifinals of this second leg of the traditional tennis grand slam.

Dent, who survived back-to-back five-setters against veteran Nicki Pilic and U.S. junior John McEnroe last week, today biltzed Brain Fairlie, 6-0, 6-2, 6-4, to reach the quarterfinals.

Top-seaeded llie Nastase, the champion of 67, played with' more fluidity and touch than in his earlier matches and reached the quarters by dispatching Jan Kodes, who has lost a couple of steps sice he was the champ here in 1970-71, 6-4, 7-5, 6-3.

They played some lovely points on the slow red clay of the center court of Stade Roland G Gryyds, but the graceful, superbly athletic Nastace was always a little too quick for Dodes, the 31-year-old who doesn't have quite the energy or agility that used to make jerky, puppet-like game so formidale.

Nastase's next opponent will be Brian Gottfried, who served and voleyed as if the sun-baked clay were a hard surface in overpowering Patrice Dominguez, the last of the natives, 6-4, 6-1, 7-5. He followed pratically every serve in an d commanded the net masterfully. Dominguez, 27, is a left-handed and coranked No. 2 in France.

Stan Smith, the only American other than Gottfried left in the men's singles, reached the fourth round by completing a 6-4, 6-2, 5-7, 7-6 victory over Czech Davis Cupper Jiri Hrebec. The match was suspended by darkness Sunday evening at 5-5 in the fourth set, but Smith served strongly in the resumption and won the tie breaker, 7 points to 1.

Solomon, who usually can match anyone in long baseline rallies, was inconsistent and ultimately impatient against Higueras, who is ranked No. 2 in Spain. He could never find any consistency in his ground strokes, served poorly and was ineffective in his occasional journeys to the net.

Solomon reverted to the "moonballing " style he used in 1972, his first appearance here, when he was referred to as "a danger to low flying sparrows." He tried to hypnotize Higueras with an assortment of lobs, loopers and slow balls, but the Spaniard responded with much of the same.

Higueras started as if he would be content to battle Solomon in the trenches for a week if necessaey. Many rallies went 30 or more strokes, both players hitting cautious topspin looper, high over the net, that hit near or inside the service lines.

Occasionally Higueras would try to set in to the behind a deeo fore-hand approach, or dart in and volley one of Solomon's parabolic strokes if it came up particulary short, but as many points were decided by unforced errors as by winners or forcing shots.

Solomon was disturbed about losing the first two sets after leading, especially after saving five set points in the second, but as a friend noted, "Even then he didn't have the old fire. He wasn't getting mad enough at himself."

Solomon hit out in the third set, abandoning the moonball for hard ground strokes, and was particularly effective with his two-fisted backhand, either down the line or cross-court at sharp angles.

Higeuras seemed to be getting tired, even after the 15-minute break between the third and fourth sets. But Solomon could not press the attack. He had great mental lapses and ragged patches in the fourth set and lost his serve from 40-0 in the fourth game and again in the eighth, when he had a total of five game points. He made unforced errors on both the break points.

"It was ridiculous. I never thought I'd lose the match," said Solomon. "I should have won the first two sets and I knew he was getting tired in thefourth, but I just couldn't get anything going."