-- Seldom have sporting moments of inconceivable pain and delirious joy covered more emotional ground yet been so difficult to distinguish. Two gripping races at Olympic Stadium on Tuesday night brought a pair of athletes to their knees and induced a flood of tears, but the sobbing of Morocco's Hicham El Guerrouj, who extinguished eight years of frustration in an excruciating sprint, was very different from that of Canadian Perdita Felicien. While he rejoiced, she was nearly blinded by grief and disbelief after a dramatic fall contributed to the first U.S. gold in the 100 hurdles in 20 years.

El Guerrouj erased the memories of two crushing Olympics past, answering rival Bernard Lagat, who came "like an avalanche" in the homestretch of the Olympic 1,500-meter final, with a straining, grimacing and, ultimately, unstoppable push for the Olympic gold that had long eluded him.

Felicien, the favorite entering the hurdles race, met calamity almost as soon as she got out of the blocks. She crashed into the first hurdle, breaking it, then upended the Russian in the lane next to her, before coming to a halt with her back against the second hurdle. American Joanna Hayes didn't notice the commotion; she won the first U.S. gold in the event since 1984 with a victory in an Olympic-record 12.37 seconds. Melissa Morrison claimed the bronze for the second straight Games, finishing in 12.56.

Euphoria and angst were entangled all day. Greek American decathlete Tom Pappas, the reigning world champion, was disconsolate after an injury forced him to withdraw from the decathlon hours before little-known U.S. teammate Bryan Clay put out the best performance of his 24 years to win a silver behind world record holder Roman Sebrle of the Czech Republic.

Russian Yelena Isinbayeva leaped in a fit of exultation as soon as she saw rival Svetlana Feofanova fail, shoulders slumping, on her last pole vault attempt. Isinbayeva then pulled one more roar of applause from the crowd of 56,000 even though it was by then after midnight, as she set a world record in the event.

While Isinbayeva drew a proper curtain on the evening's drama with the vault of 16 feet 11/4 inches, El Guerrouj, minutes removed from his victory lap, wound his way through microphones and cameras, laying out the most personal of feelings without apology or awkwardness. This man, after all, owns the world record in the event and four world titles, but the prize he had wanted most he feared he could never obtain.

In 1996 in Atlanta, he was on his way to the gold before tripping with one lap to go. In 2000 in Sydney, he lost a sprint to the finish to Kenyan Noah Ngeny. Then, much like Tuesday, he cried, then apologized for letting down his entire nation.

"Four years ago, I cried tears of sadness," he said through a translator, still blinking back tears. "Today, I cry tears of joy. I'm like a 4- or 5-year-old child here weeping. . . . I came back from very, very far down. . . . And I won today. I can't explain my joy. I can't explain how I feel."

At 200 meters, El Guerrouj took the lead, unsatisfied with the slow pace. Lagat stayed with him until the final turn, then tried to make his move. As the pair came into the homestretch, they were nearly shoulder to shoulder, and they ran that way through 50 meters. Lagat, then, inched into the lead.

As fans gasped, El Guerrouj did not whither. With gritted teeth, he managed to push himself to victory, crossing the finish line in 3 minutes 34.18 seconds. Lagat finished in 3:34.68, with Portugal's Rui Silva in third in 3:34.68.

"I knew the strength he had," El Guerrouj said. "He really came back at me. It was like an avalanche, that was really the sensation. I really was going 101 percent. . . . In the last 50 meters, the first thing I thought about was Sydney . . . and I found the energy to really kick."

When El Guerrouj crossed the finish line, he covered his face with his hands and fell to the track, kissing it. Lagat sought him out almost immediately, bending over to offer an embrace.

"That extra one percent propelled him to the win," Lagat said.

In contrast, the hurdles final didn't seem to be about who wanted it more. It hinted at fate, blind chance, karma. Then again, who is to say what would have happened had Felicien, the reigning world champion, kept her feet? Hayes ran a beautiful race, topping an Olympic record that had stood for 16 years. The time was also the fastest of the year, topping Felicien's world best by .09 seconds.

"It's hard to stay on your rhythm when someone is pushing you," U.S. women's sprint coach Curtis Frye said. "No one has ever been in front of [Felicien]. It's the first time she ever experienced it. She's a great champion, but this is a good experience for her."

Indeed, Felicien rushed out of the blocks so hurriedly she stepped short into the hurdle, pushing it over with her heel. She then rolled into the side of Russian Irina Shevchenko, sending her sprawling. When Felicien found herself with the back resting against the second hurdle, staring at the start line, the race going on without her, she crossed her arms miserably and cried. Later, she spiked her shiny red shoes to the track.

"My initial reaction was, this is a dream," she said. "I'm shocked. I am on the ground, and they are up running. . . . This is so devastating, so hard to swallow."

After the race, she spent about 15 minutes talking with former hurdles champion Renaldo Nehemiah, who embraced her for a long time. Her eyes were red from crying when she reached a group of reporters.

"Everyone feels for her," fellow Canadian Angela White said. "She was in fantastic shape. It's difficult when that happens."

It wasn't difficult for Hayes, 27, who competed in the shadow of Gail Devers until Tuesday night. Devers, 37, who failed to advance to the final, has never won an Olympic medal in this event. Hayes, a UCLA graduate whose biggest achievement to date was a Pan-American Games gold last year in the 400 hurdles, did the right thing in the race: She never looked back.

Felicien's Olympic dreams were crumbling and Hayes was off and running.

"I didn't hear a thing," she said. "I was so focused on what I was doing."

Joanna Hayes wins the first U.S. gold medal in the 100-meter hurdles since 1984 with a victory in an Olympic-record 12.37 seconds. Canada's Perdita Felicien comes to a halt against the second hurdle after crashing into the first hurdle and upending the Russian in the lane next to her.