As Kory Tarpenning pole vaulted into the dark Indianapolis night, he seemed to have plenty of height to clear the record-high cross bar. That is, until he brushed the bar on the way down, and then the two of them seemed bound to fall together. Except, wait, some two stories in the air, Tarpenning quickly reached out with both hands and pushed the bar back in place. With that little sleight of hand, as someone called it, Tarpenning ensured himself a victory in the pole vault competition of the U.S. Olympic Track and Field Trials Thursday. He also set a meet record of 19-3 3/4, the third highest vault ever by an American.

"Yeah, I put my hand on the bar to steady it," said Tarpenning with a smile. "Earl did the same thing."Earl was Earl Bell, the balding 33-year-old veteran of the pole vault wars who finished second to Tarpenning by using his own sleight of hand on a successful clearance of 19-0.

Such hands-on pole vaulting is not illegal, but some observers think it ought to be. "It should have to be a clean jump over the bar," said Bell. "I wish they would change the rule." Then, with a smile, Bell added, "I wish they would have changed it right after I made my jump."

That's because Tarpenning, a 26-year-old former University of Oregon star, followed Bell's performance with his record clearance and thus won the competition. It was the first major victory of his career.

Tarpenning entered the competition at 18 feet and cleared the height on his first attempt. He proceeded to clear 18-4 and 18-8 on his first attempts, then missed his first attempt at 19 feet. He made his second attempt at that height, then cleared 19-3 3/4 on his first attempt. It was a height that only eight men have ever bettered. Tarpenning then made three attempts at 19-7, which would have been an American record, but came up short.

"I got a little tired at the end," said Tarpenning.

Undoubtedly, so did one Tim Bright. After finishing two days of competition in the decathlon Thursday afternoon, Bright went directly to the pole vault competition. Why? "Because it's never been done before," said Bright, who is also a world-class pole vaulter. For Bright, a day that began at 5 a.m., finally ended at about 10 p.m. with a fourth-place finish in the pole vault. Both Bright and Billy Olson cleared 18-8, but Olson was awarded third place on the basis of fewer misses. After setting 11 world records during the past decade, Olson, who turned 30 this week, finally had made his first Olympic team.

Bright was not completely left out of the Olympic picture; he finished second in the decathlon and narrowly missed winning what proved to be a remarkably close competition - one in which 48 points separated third place from first. Gary Kinder was the winner, with 8,293 points, followed by Bright with 8,287 points, and David Johnson with 8,245.

"8,300 points in these conditions is world class," said Kinder. Indeed, the decathlon began in a heavy, cool rain on Wednesday and ended in the heat on Thursday.

Bright might well have won the decathlon had he not jogged through the final event, the 1,500-meter run, in an apparent effort to save himself for the pole vault. Bright finished 12th in the 1,500 with a time of 4:45.12. With any kind of stronger finish he would have beaten Kinder, whose 70-point lead shrunk to six points with his 15th-place/4:55.39 performance in the 1,500.

"I decided at the start of the year that I would be a decathlete this year and a pole vaulter next year," said Bright, who cleared 18-4 1/2 in the decathlon pole vault.

Aside from the decathlon, pole vault and women's discus (won by Connie Price with a throw of 194-3), Thursday was devoted to trial heats, which proceeded uneventfully. Today's competition, however, could be anything but eventful, as Florence Griffith-Joyner begins her assault on another world record and world champion Greg Foster tries to make the Olympic team while hurdling with a cast.

Griffith-Joyner, who last weekend ran the three fastest 100-meter dashes ever by a woman, has said she will try to lower the world record of 21.71 in the 200 as well. She will run in the first and second rounds today.

Foster, the defending world champion in the 110-meter high hurdles, has said he will compete in the trials despite a broken arm that required 12 screws to repair. He also will run in the first and, presumably, second rounds today.

In Thursday's heats, Mary Slaney ran away from the field to win her semifinal heat of the 1,500-meter run with a time of 4:04.27 - some five seconds ahead of Kim Gallagher, her nearest rival. Slaney, who won the 3,000-meter run on Sunday, says she will attempt to run under four minutes in Saturday's final (her American record is 3:57.12).

"Things are coming around," said Slaney. "Now I'm starting to feel like I can run fast."

America's top two milers, Steve Scott and Jim Spivey, coasted through their first-round heats in the men's 1,500-meter run. Scott won his heat with a time of 3:42.92; Spivey was fourth in his heat in 3:44.12.

In the second round of the women's 100-meter hurdles, Gail Devers, the co-American record holder, set a meet record of 12.83.