Andre Agassi acknowledges the crowd Sunday after losing to Benjamin Becker at the U.S. Open tennis tournament in New York. Photos by The Associated Press. Andre Agassi waves to the crowd as he leaves the court after Sunday's loss at the U.S. Open.

NEW YORK -- As the cheers rained down on him from every part of cavernous Arthur Ashe Stadium, the sweat on Andre Agassi's brow gave way to tears.

The eyes, which for 20 years had been so piercing, so sharp in pinpointing weaknesses in his opponents for exploitation on the tennis court, grew cloudy with mist.

Moments before, the 36-year-old Las Vegan's highly successful career had come to an end Sunday, losing in the third round of the U.S. Open to unheralded Benjamin Becker. The 7-5, 6-7 (4), 6-4, 7-5 defeat closed the book on one of the greatest eras for U.S. men's tennis as Agassi joined fellow champions Pete Sampras, Jim Courier and Michael Chang in retirement.

Agassi had not planned a speech for when he was through playing in his 21st and final Open. But after sitting and hearing an eight-minute standing ovation from the 23,712 fans, an ovation that spread to the adjoining courts on the grounds of the USTA Billie Jean King National Tennis Center, Agassi felt compelled to take the microphone and thank the New York audience for its support.

"The scoreboard said I lost today, but what the scoreboard doesn't say is what I have found, and over the last 21 years, I have found loyalty," Agassi told the crowd, many of whom were weeping with him. "You have pulled for me on the court and also in life.

"I've found inspiration. You have willed me to succeed sometimes even in my lowest moments. And I've found generosity. You have given me your shoulders to stand on to reach for my dreams -- dreams I could never have reached without you.

"Over the last 21 years, I have found you, and I will take you and the memory of you with me for the rest of my life. Thank you."

After Becker's 133-mph serve at match point whizzed past Agassi, the Las Vegan gave the fans his customary bows and kisses to all four sides of Ashe Stadium. This time, as he prepared to pick up his bag and exit the grand stage for the final time, Agassi gave an encore thank you, bowing and blowing tearful kisses to the appreciative crowd.

The ovations continued when he reached the locker room as his fellow players stood and cheered. And in a rare display of emotion, he was accorded a standing ovation from many members of the media at the end of his post-match news conference.

"Are you guys really going to miss me, or are you just acting like that?" Agassi said as he left the podium in the interview room.

The winner of 60 singles titles, including eight Grand Slams, three Davis Cups and Olympic gold in 1996, Agassi was hoping to go out in a blaze of glory at Flushing Meadows. However, he knew his aching back could hold up for only so long and, despite a cortisone shot earlier in the week and three consecutive days of receiving injections of Toradol, an anti-inflammatory, Agassi hardly could move on the hard-court surface.

Still, he had his chances, and had he been able to break Becker's serve in the third set when the match was even and up for grabs, he might still be playing today.

Instead, the 25-year-old German, who is no relation to former tennis great Boris Becker, played himself into history as the man who ended Agassi's career.

"It was a tough, emotional moment for me, too," Becker said. "I was happy, obviously, and at the same time, I was sad. It was a once-in-a-lifetime experience for me."

Agassi's family and inner circle knew that Sunday could be the day it all ended. The heavy rains that soaked the New York metropolitan area Saturday gave Agassi a day's reprieve as his match got pushed back to Sunday. But they also knew Agassi was living on borrowed time with his balky back.

"It's his journey, and he's traveled it for 21 years," said Perry Rogers, his best friend and longtime manager. "It was tough for him to go out there. But it's been an amazing run, and (Sunday) was the exclamation point."

Agassi's older brother, Phil, also was emotional as he talked about the end of a remarkable tennis career.

"I think Andre's actions as a tennis player and as a man reflect who he is," Phil Agassi said. "Come hell or high water, he was going out on his terms and giving it all he had this week. This is a moment that's second to none."

His wife, former tennis superstar Steffi Graf, her reddened eyes displaying the pain she was feeling, left with their 2-year-old daughter Jaz in her arms, not stopping to speak with reporters.

Agassi's parents, Mike and Betty, already had returned to Las Vegas when Agassi stepped on the court Sunday. Earlier in the week, Mike Agassi said he was proud of his son's accomplishments and had wanted to be in New York to share some of the final U.S. Open experience with him.

"There is nothing to regret," Mike Agassi said. "He is a great champion. Wouldn't you be proud if he were your son?"

Friday, Mike Agassi told ABC News that he wanted his son to quit after he defeated Marcos Baghdatis in five tough sets Thursday night. On Sunday, Andre said there was no way he was doing that.

"If I wanted to quit, I would have done that a long time ago," he said. "I didn't come here to quit."

Agassi was hobbling badly as he made his way through a phalanx of well-wishers to the waiting white Lexus SUV that was to whisk him back to Manhattan. But he could take solace in the fact that when he wakes up this morning to do the rounds on the morning television talk shows before heading back to his Summerlin home, he won't have to worry about preparing to play a competitive tennis match. His Toradol and cortisone days appear to be over.

"Let me put it this way," Agassi said. "I don't care how I feel physically. I haven't felt that way before.

"You've always had to be somewhere thinking about being somewhere else. I look forward to being wherever I am."