All Downhill for Lendl Now : Tennis: He used to be feared in the sport as Ivan the Terrible. Currently, that pretty much describes his game.

Ivan Lendl said he supposes his game will come around again. But when?

It didn’t at the French Open Friday, where Lendl lost in the second round to Jaime Oncins, a 21-year-old unheralded Brazilian.

In Lendl’s first appearance on the stadium court at Roland Garros Stadium since his memorable loss to Michael Chang in the fourth round in 1989, he squandered a chance to win in the fifth set and lost, 3-6, 3-6, 6-3, 6-2, 8-6. The match had been halted by rain Thursday with the deciding set tied, 5-5.

Lendl’s slide in the world ratings began on these red clay courts two years ago, when Chang, then 17, rallied from a two-sets-to-none deficit. Chang, suffering from cramps and even serving underhand at one point, wore Lendl down psychologically, effectively destroying the veteran player’s confidence. Chang, whose shocking victory on that occasion--over a player who had always given the impression that he would be unbeatable in this sort of situation--recovered in time to win three more matches, including a five-setter over Stefan Edberg in the final.

Oncins needed no such skulduggery. A human backboard who thrives on slow clay surfaces, Oncins held off four break points in the 11th game of the final set, then stayed with Lendl, 32, until the 14th game.

Lendl, serving at 7-6, won the first point, but quickly got into trouble. At 15-40, he returned a drop shot by Oncins with one of his own. But the spindly, 6-foot-4 Oncins got to the shot and cranked a stinging backhand down the line for the match. While Oncins went into a crouch and then a celebration dance, Lendl quickly walked away in disgust.

“You have to take a risk for a winner (against) a guy like Lendl,” said Oncins, ranked 72nd.

Lendl has won eight Grand Slam tournaments, but his fortunes have toppled since the defeat by Chang. Last week, for the first time in 615 weeks--almost 12 years--he was not ranked among the top 10, holding down the No. 11 spot. And Friday’s loss marked his earliest departure from a Grand Slam tournament since a first-round defeat at Wimbledon in 1981.

Lendl has pointed to the Chang match, and last January’s disappointing 4-6, 7-5, 6-1, 6-7, 6-4 loss to Stefan Edberg at the Australian Open, as losses that have haunted him. Although he said Friday that he does not doubt his ability, his struggle continues.

“Not everything can go your way all the time,” Lendl said. “Usually when something starts going bad, it starts piling up.”

Lendl also has been bothered by the aftereffects of last year’s wrist surgery for benign tumors. The surgery forced him to skip the French Open then, but he also was absent here in 1990, saying he wanted to concentrate on grass-court play in preparation for Wimbledon, the only Grand Slam he has not won.

Age probably has been a factor in Lendl’s problems, and the game has changed since he was a junior champion and tennis seemed so easy.

“Anybody can keep the ball in play these days,” Lendl said. “So, if you just start hitting the ball back and not attack, you are going to get in trouble.”

Lendl, seeded 10th, definitely tried here. Behind his cool facade, he played with passion. But Oncins, playing in his second French Open, was not intimidated.

“He played a little bit nervous,” Oncins said. “I just played relaxed.”

Edberg, seeded second, never got a chance to relax in another rain-delayed marathon. This one, though, on Center Court, kept the order of things in place, as the Swede edged Gabriel Markus of Argentina, 4-6, 7-6 (7-1), 7-5, 4-6, 6-4.

Markus, 22, of Buenos Aires, has done well against top-10 players in the past, but never at a Grand Slam on center court. Markus, who reached the third round of the French Open last year, rallied in the fourth set when play resumed on a cloudy, cool day in Paris. He began the day trailing, 3-1, after three arduous sets Thursday.

Edberg characterized Markus’ backhand as one of the strongest in the game today, and the Argentine used it effectively to force a fifth set. The set was tight, but Edberg remained collected.

When Markus took the ball to serve at 4-4, it was time for Edberg to take control. Edberg steadily made winner after winner, forcing Markus to serve four break points. Eventually, the pressure was too much, and after a long rally, Edberg finally forced his opponent to hit a backhand long.

“I was a bit tense,” Markus said.

Edberg, who survived a difficult four-setter in the first round against France’s Oliver Soules, faces Andrei Cherkasov, a tough clay court player from Moscow, in the third round.

Tennis Notes

Jim Courier, ranked No. 1, continued his sharp play here, winning his 19th match in a row by defeating Alberto Mancini of Argentina in the third round, 6-4, 6-2, 6-0. . . . No. 14 Alexander Volkov of Russia was upset, losing to Germany’s Carl-Uwe Steeb in straight sets. . . . No. 8 Goran Ivanisevic of Croatia won a marathon over Sweden’s Magnus Larsson, 6-7 (7-5), 6-3, 6-1, 3-6, 9-7. Andre Agassi, seeded 11th, lost a set for this first time in three matches, but advanced, beating Croatia’s Goran Prpic, 2-6, 6-4, 6-1, 7-6 (7-4).

Andrei Medvedev of Ukraine, at 17 the youngest player in the men’s field, became the first to reach the fourth round, beating Australian Todd Woodbridge, 7-6 (7-5), 6-2, 6-1. Medvedev, playing his first Grand Slam, has lost only one set in three matches. Pete Sampras, seeded third, also advanced to the fourth round by defeating France’s Rodolphe Gilbert, 6-3, 6-2, 6-3. Spain’s Carlos Costa, No. 9, advanced with a 2-6, 6-2, 6-2, 6-2 victory over South African Wayne Ferreira.

Winning suspended second-round matches were Michael Chang, 6-3, 2-6, 6-3, 6-0 over Spain’s Marco Aurelio Gorriz, and No. 13 Aaron Krickstein, who outlasted fellow American MaliVai Washington, 4-6, 5-7, 6-4, 7-6 (9-7), 6-3.