Kurt Thomas gave perhaps the greatest performance in the history of American gymnastics tonight, shocking even himself as he finished second (to a Russian) in the men's prestigious all-around competition at the World Championships.

In a European country, the cocky 5-foot-6 Thomas -- a 127-pound ball of grace and muscle -- might have been carried through the streets on the shoulders of his countrymen.

After all, no American in the long history of gymnastics has ever won a medal in the all-around, a six-events-in-one-night competition hallowed as the pinnacle of the gymnastics universe.

Like most Americans, however, the crowd of 10,000 in the one-third empty Tarrant County Convention Center didn't even give Thomas a standing ovation -- presumably unaware that no man or woman had come close to his feat.

Thomas himself was the previous highest American finisher in the World Championships, taking a sixth in 1978. Now, only one man can call himself Thomas' superior -- Alexandre Ditiatin of Russia, who edged the American, 118.250 to 117.975.

"I couldn't have done much better," said the nimble Thomas, who was most spectacular with near-perfect scores of 9.9 in the pommel horse and vault (the best vault of his life). "This was as well as I've ever performed. My goal, to tell the truth, was just to finish third -- if I could."

This was a dazzzling night for U.S. gymnasts, as Bart Conner finished fifth -- higher than any American ever climbed before tonight -- while Jim Hartung tied for ninth.

"I can't believe we have three people in the top 10," crowed Conner. "The Russians are still very, very great, but I can see the day on the horizon when America will win the world team championship."

Indeed, tonight marked a changing of the imperious and phlegmatic Russian guard as the 5-foot-8 1/2, 153-pound Ditiatin supplanted defending world champion Nikolai Andrianov as the U.S.S.R.'s boss of biceps.

Andrianov, who dominated world gymnastics in the '70s and was Olympic champion in '76, did not qualify for this evening's finals. Russia, nevertheless, finished a spectacular first-third-and-fourth, with Alexandre Tkatchev (117.475) winning the bronze medal and Vladimir Markelov taking fourth (117.275).

"Ditiatin is like a big machine that just chugs along turning out 9.9s as though he doesn't know how to do anything else," said Conner. "He never makes a mistake and his upper-body strength is incredible."

The contrast between Thomas and Ditiatin was stark -- almost as though they participated in two different sports.Thomas fairly flew threw the pommel horse -- firing off his famous toes-to-the-sky Thomas Flairs, and bounced all over the mat on the floor exercises. Ditiatin, with the arms of an NFL tight end attached to a 153-pound body, looked like a syrupy, slow-motion version of Thomas.

However, in the spectacular power events -- particularly the heavenly rings -- Thomas' exercises were a portrait in total strain, while Ditistin's were controlled majesty.

"Ditiatin's routines haven't increased much in risk," said Thomas, "but he's solid all the way . . . I thought I had a great night, but I took a few minor steps (missteps) which caused him to beat me."

Then, Thomas graciously conceeded that Ditiatin was still in a slightly higher league than he. "I started the night second, but I didn't think much about moving up (on Ditiatin). I mostly wanted to stay where I was."

These World Championships -- a six-ring simultaneous circus -- had never before been held outside of Europe, but the Texas crowd did its enthusiastic, if novice, best to encourage the Americans.

"The crowd fires you up, even if it doesn't affect the judges," said Conner, whose previous best in all-around was ninth in '78. "It builds a nice atmosphere and I think it boosted us all."

The throng chanted "Let's go, Kurt," and spelled "T-H-O-M-A-S," although the clearest yell, during a moment of silence, was a Texas football fan screaming, "Hook 'em Horns."

Thomas began the night .175 behind Ditiatin and stayed on his heels all night. After each exercise, as the 36 finalists rotated to the next station, Thomas would give a fist-raised salute to his wife Beth in the crowd.

"I didn't say anything special to him," she said. "He only has one superstition. He forbids you to wish him luck. He doesn't believe there is any such thing."

When Thomas wasn't ripping off 9.85s in the high bar and floor exercise, and a decent 9.80 in the rings (his weakness), he was yelling in a penetrating voice to his teammate Connors: "Let's go, Bart!"

"Yes, I heard him," said Connors, who is usually Thomas' nip-and-tuck archrival among American gymnasts. "It's hard to say how incredibly encouraged I am. A year ago I was almost perfect in the World Championships . . . one little mistake . . . and I could finish only ninth.

"Now, I've improved overall, especially in difficulty, to the point where I made four serious mistakes tonight -- almost four major breaks -- and I finished fifth. For the first time I realize that I could win this whole thing someday."

As the final event approached, Thomas still trailed Ditiatin by that small but significant .175 margin. But Thomas knew it was partially an illusion.

"I saw the scoreboard and I knew I couldn't win," said Thomas. "Ditiatin's last event was the rings -- his best. Mine was the parallel bars -- not my best."

Thomas gutted his way to a final 9.80, then watched Ditiatin close the show with the most transporting effort of the night. With his first World Championship in sight, the 22-year-old Ditiatin soared like some great white snow bird as he held interminable handstands in the quivering rings.

Finally, with a double somersault dismount, Ditiatin returned to earth. And Texas capitulated -- cheering a Russian.

Nonetheless, America's poor name in gymnastics had been cleansed. The night before, America's highly touted women had failed -- finishing sixth as a team.

U.S. women's coach Linda Metheny Mulvihill was so infuriated that she told her team today that they were "fat", and that "if they weren't careful we could have an entirely different (six-woman) team by the time the Olympics arrive."

America's men -- Thomas, Conner and Hartung -- rose as high as the women had sunk low the night before.

"I was proud of Hartung," said Thomas. "He didn't look very good in the gym. He didn't work very hard. But when he got out there tonight, he looked great. He came through when it counted."

That, of course, could be said of the 23-year-old Thomas, the bubbly chap who cannot keep from telling the truth -- even if it is often curt.

Asked what was on his mind in his moment of victory, Thomas might have talked of Moscow dreams. But this was the self-assured man who, after becoming the first American since 1932 to win an individual-event gold medal in the World Championships in '78 when he won the floor exercises, went to his hotel and immediately fell asleep.

"I won't celebrate," Thomas said matter-of-factly. "But I sure am hungry. Let's eat."