More than an hour after hitting one last shot as a professional tennis player, then delivering one last, voice-wavering speech to an adoring U.S. Open audience, Andy Roddick exited the locker room one last time.

Accompanied by his wife and other family members, a black baseball cap tugged low over his eyes, Roddick slung a racket bag off his aching right shoulder — the one responsible for so many high-speed aces, violent forehands and the most recent Grand Slam title by an American man — and tossed the equipment in the back of a waiting van.

Won't need that any longer.

Serenaded by choruses of "Let's go, Andy!" that rang through Arthur Ashe Stadium in the closing moments of his career, the 2003 U.S. Open champion headed into retirement with a 6-7 (1), 7-6 (4), 6-2, 6-4 loss to 2009 champion Juan Martin del Potro of Argentina in the fourth round at Flushing Meadows on Wednesday.

"If we do badly, then it costs us something; if we do well, we get great things. This was about something bigger. It wasn't about ranking points or paychecks or anything else," Roddick said. "This week I felt like I was 12 years old, playing in a park. It was extremely innocent. That was fun. I enjoyed it."

His defeat was significant, if not as unexpected as top-seeded Roger Federer's 7-6 (1), 6-4, 3-6, 6-3 quarterfinal loss was several hours later against No. 6 Tomas Berdych of the Czech Republic. Federer won five of his record 17 Grand Slam championships at the U.S. Open and was bidding to reach the semifinals in New York for the ninth consecutive year.

But Federer's famous forehand was way off most of the evening, while the 6-foot-5 Berdych kept pounding fast serves and dangerous groundstrokes right where he wanted them. It was Berdych's fourth victory in his last seven meetings against Federer, including in the 2010 Wimbledon quarterfinals en route to a runner-up finish there.

"There is something in my game that he doesn't like," Berdych said.

Now he will play Olympic champion Andy Murray for a berth in the U.S. Open final.

"I wish I could have played better," said Federer, whose 40 unforced errors were nearly twice as many as Berdych's 21. "So many moments I thought, 'Man, it's just not happening for me.'"

Roddick's earlier goodbye was bittersweet. For the fans who gave him a standing ovation at the end — del Potro joined in, rising from his changeover chair to applaud — and for Roddick himself.

He covered his face with a white towel while seated on the sideline after sailing a running forehand long with the final swing of his racket. Earlier, he appeared to be trying to avoid crying while serving in the next-to-last game; in the stands, his wife, model-actress Brooklyn Decker, stuck a finger underneath her sunglasses to wipe away tears.

"Playing the last five games was pretty hard. Once I got down a break, I could barely look at my (guest) box," Roddick said during a news conference sprinkled with the sort of witty one-liners he quickly came to be known for after turning pro in 2000. "I don't know what the emotions are. I'm a little overwhelmed right now. I normally feel like I can grasp things pretty quickly and clearly. I certainly don't feel that way right now."

During an on-court address to the crowd, Roddick got choked up, particularly when making a reference to his longtime agent, Ken Meyerson, who died last year.

When handed a microphone, Roddick began by saying: "Oh, wow. For the first time in my career, I'm not sure what to say."

"Since I was a kid, I've been coming to this tournament. I felt lucky just to sit where all of you are sitting today, to watch this game, to see the champions that have come and gone," Roddick told the fans in a moment reminiscent of Andre Agassi's farewell speech at the 2006 U.S. Open after his final match. "I've loved every minute of it."

It was appropriate that Roddick would leave tennis at Flushing Meadows, which is why he surprisingly announced last Thursday, his 30th birthday, that the U.S. Open would be his final tournament. A perfect bookend: He visited the hard-court Grand Slam tournament at age 9, a trip his parents gave him as a birthday present.

He would go on to win a junior title in New York, then the 2003 men's trophy at age 21, allowing him to end that season No. 1 in the ATP rankings. He later participated in four other major finals — one at the U.S. Open, three at Wimbledon — and lost each to Federer, including a 16-14 fifth set at the All England Club in 2009.

"In my mind," Federer said last week, "he is a Wimbledon champion."

Federer, of course, really is a Wimbledon champion, seven times in all, while Berdych is still seeking his first major title anywhere. But Berdych is exactly the type of player who can give Federer trouble, a tall guy who hits the ball hard.

there is something in my game that he doesn't like

Roddick finished with a record of 612-213 (a winning percentage of .742). He won 32 tournament titles, led the United States to the 2007 Davis Cup championship, and injected a say-what-you-think personality into his sport.

"People always try to beat him up: 'You should have won more.' No, he got the maximum out of his game," said Roddick's coach, Larry Stefanki. "He's a man of his word. A phenomenal competitor. He got all the hard work in. He prepared. He was a true professional. And he learned a lot over the years. He did it the right way. He's a first-vote Hall of Famer, no doubt in my mind. He can downplay that all he wants, but it's not even close, in my opinion."

Del Potro's quarterfinal opponent Thursday will be defending champion Novak Djokovic, who advanced when No. 18 Stanislas Wawrinka stopped playing Wednesday because of illness and fatigue while trailing 6-4, 6-1, 3-1.

Djokovic's Serbian Davis Cup teammate, No. 8 Janko Tipsarevic, finished his rain-interrupted 6-3, 7-6 (5), 6-2 victory over No. 19 Philipp Kohlschreiber, and faces No. 4 David Ferrer on Thursday.

Murray was the first man into the semifinals, turning things around after being a point from a two-set hole against 12th-seeded Marin Cilic and winning 3-6, 7-6 (4), 6-2, 6-0.

Like Murray, four-time major champion Maria Sharapova constructed quite a comeback in her quarterfinal, erasing a 4-0 deficit and defeating 2007 Wimbledon runner-up Marion Bartoli 3-6, 6-3, 6-4. Sharapova is 12-0 in three-set matches this season.

"It shows that I enjoy the battle, no matter what the score is," Sharapova said.

No Sharapova-like or Murray-esque theatrics were required by Serena Williams, who has won three of her 14 Grand Slam titles at the U.S. Open. She hit 12 aces in her latest dominant performance, a 6-1, 6-3 victory over 2008 French Open champion Ana Ivanovic.

Williams' semifinal opponent will be 10th-seeded Sara Errani of Italy, who eliminated her good friend and doubles partner, No. 20 Roberta Vinci.

Before the drama of Berdych vs. Federer under the lights at night, the story of the afternoon was Roddick's departure — from the tournament and from tennis.

A series of injuries, particularly to his shoulder, made it tough for Roddick to remain in the game's upper echelon. A member of the top 10 at the end of nine consecutive seasons, he slid to 34th in March, his lowest ranking since 2001. A hurt right hamstring forced Roddick to retire during his second-round match at the Australian Open, and he lost in the first round at the French Open and third at Wimbledon.

After getting past three opponents ranked outside the top 40 in New York, Roddick faced a more daunting challenge in the seventh-seeded del Potro.

The last set won by Roddick was the first of his match against del Potro. After Tuesday night's suspension because of rain, they resumed with Roddick ahead 1-0 in the opening tiebreaker, and he needed only four minutes to wrap it up Wednesday, fresh and strong as can be, while del Potro was rather sluggish.

The key was the second set. This time, it was del Potro's turn to take control of a tiebreaker. Gaining more traction on his opponent's once-all-powerful serve, del Potro whipped a cross-court forehand return right at Roddick's feet on set point.

The momentum swing continued when del Potro broke to begin the third set. He hit a drop shot that Roddick chased, grunting loudly, and eventually del Potro deposited a passing winner that left Roddick hanging his head.

Del Potro broke again for a 3-0 edge, producing a drop shot Roddick didn't chase. As he walked to the changeover, Roddick grimaced and flexed his right shoulder — the one that hit a then-record 155 mph serve years ago but isn't what it used to be. He jokingly referred to it as "Hamburger Helper" after his previous match.

When Roddick double-faulted, then missed a forehand, to fall behind 3-2 in the fourth, the competitive portion of the match was essentially done. The rest of the way was a chance for spectators to salute a guy who always wore his emotions on his sleeve while being the best U.S. men's tennis player for about a decade.

"It's been a road of a lot of ups, a lot of downs, a lot of great moments. I've appreciated your support along the way," Roddick told the crowd. "I know I certainly haven't made it easy for you at times, but I really do appreciate it and love you guys with all my heart. Hopefully I'll come back to this place someday and see all of you again."


Follow Howard Fendrich on Twitter at http://twitter.com/HowardFendrich