John Isner smashes his racquet in the fifth set of Sunday's match (screengrab via YouTube)

The U.S. Open represented John Isner's final opportunity to make a deep run at a grand slam this year, so the hard-serving American didn't take it well at all when that chance evaporated Sunday night.

Isner lost his cool after a key foot fault call while he was serving in the fifth set of a 6-4, 3-6, 4-6, 6-3, 6-4 loss to No. 19 seed Philipp Kohlschreiber. He double-faulted after what would have been an ace was negated by the foot fault, giving Kohlschreiber a break point that he converted for the lone break of the fifth set.

Irate over the timing of the call, Isner whacked a ball into the upper deck, drawing a code violation for unsportsmanlike conduct. He spent much of the ensuing changeover arguing with chair umpire Carlos Bernardes over the line judge's call, telling him incredulously, "I haven't foot-faulted this whole year, and this guy calls one on me."

Isner was still seething at the ensuing changeover two games later. He again had words with Bernardes before smashing his racquet on the ground and flinging it away from him, a show of force that would have left even guitar-smashing '80s rock stars in awe.

The frustration from Isner probably had as much to do with how the match went for him as the foot fault call itself. He converted on just two of 11 break-point chances. Kohlschreiber, on the other hand, capitalized on all three of his, including an Isner double-fault at 3-4 in the fourth set that enabled the German to force a fifth.

If Isner is the best hope for American men's tennis to remain relevant post-Andy Roddick, then this year so far has been a mixed bag.

Sasha Vujacic and Maria Sharapova in happier days. (Getty Images)-Follow Jay Busbee on Twitter at @jaybusbee.-

Tune up those backhands, gentlemen. Maria Sharapova is back on the market.

After taking down Mallory Burdette in straight 6-1 sets on Friday in the third round of the U.S. Open, Sharapova revealed that her engagement to -- indeed, her entire relationship with -- former Laker Sasha Vujacic is finis. And she did so via what must be a first with celebrity engagement breakups: not only did she not dodge the question, she wondered why it hadn't been asked before:

"It's been since the end of spring actually," Sharapova said. "I was waiting for someone to actually ask me that question, but nobody did directly."

Sharapova was able to remain focused on tennis, winning the French Open earlier this season to complete a career Grand Slam. She's now in the round of 16 in the U.S. Open for only the second time since winning the Open in 2006.

The culprit behind the breakup? The dueling career demands of two globetrotting athletes. "It was a really nice

Instead of continuing a slow fade from the peak of men's tennis to the outskirts of the top 20, Andy Roddick has decided to step away from the sport.

Roddick, 30, announced at a press conference Thursday he will retire after the U.S. Open, meaning a man who has been the face of U.S. men's tennis since Pete Sampras and Andre Agassi retired could be passing the torch as soon as this week. The first chance for Roddick to extend his farewell tour will come Friday when he meets talented 19-year-old Australian Bernard Tomic in the second round of the U.S. Open.

"On some big moments this year, I think I've known I was done," Roddick said. "Walking off at Wimbledon, I felt like I knew. Playing here, I don't know what it was, but I couldn't imagine myself being here in another year.

"Whatever my faults were, I've always felt like I've never done anything halfway. This is probably the first time in my career that I can sit here and say, I'm not sure I can put everything into it physically and emotionally. I don't know if I want to disrespect the game by coasting home."

[Related: Venus Williams ousted in the U.S. Open second round]

Roddick has been the best American men's player for much of the past decade, reaching No. 1 in the world for the first time in Nov. 2003 and amassing 32 ATP World Tour titles and 33 Davis Cup victories. His lone grand slam title came at the 2003 U.S. Open, but he reached the finals of Wimbledon three times, falling to Roger Federer each time including a 16-14 fifth-set heart breaker in 2009.

The departure of Roddick will again shine a light on the dearth of young American tennis talent capable of filling the void.

Ryan McIntosh in action. (Via @usopen)

If you're one of the 250 people chosen to serve as a ball person at the U.S. Open, here's what you can look forward to: long hours spent in perpetual, knee-creaking vigilance, and chasing down errant shots and missed serves in speed and silence. All this for $7.75 an hour. Above all, do your best to be neither seen nor heard.

For most ball people, that anonymity isn't a tough challenge. They do their jobs so fast they've left your mind before the next point even starts.

Most, but not all. Meet Ryan McIntosh, a 23-year-old ball boy from Texas. He's an Army veteran who's doing everything his colleagues are doing even though he lost a leg in Afghanistan. And, like so many in his position, he's not letting the prosthesis below his right knee define him:

"I don't look at myself as being disabled or handicapped or anything else," McIntosh told the New York Daily News. "I want to experience everything, and live life to the fullest."

He's doing exactly that; a family man and a counselor

Venus Williams (AP)Whether it was the canary yellow lattice-style top she wore at the Australian Open last year or the racy red-trimmed black dress she donned at the French Open months later, Venus Williams' grand slam attire has sometimes turned heads for all the wrong reasons.

Venus Williams (Getty Images)

Maybe that's why the colorful rose print dress she wore in her opening-round U.S. Open match Tuesday evening seemed tasteful and demure by comparison.

Yes, it was a bit non-traditional by tennis standards. Yes, the print of the fabric might be just as well-suited for a sofa or set of drapes. But the self-designed dress looked flattering on Williams as she overpowered fellow American Bethanie Mattek-Sands 6-3, 6-1 at Arthur Ashe Stadium.

What will be more important to Williams than the positive reviews for her dress is that her game inspired plenty of compliments as well. Behind a potent first serve and powerful ground strokes, she overcame a few tentative early games and dismantled Mattek-Sands in the second set.

The strong performance takes on added significance because this has not been an easy year for Williams. Diagnosed with an autoimmune disease that she announced at last year's U.S. Open, the 32-year-old lost in the first round at Wimbledon and the second round at the French Open, suggesting that perhaps her days of contending at high-profile events were behind her.

Williams showed signs of life during the hard-court season in reaching the semifinals at Cincinnati earlier this month, but duplicating that sort of run at the U.S. Open will require some of her biggest wins in recent memory. Up next for Williams on Thursday is sixth-seeded Angelique Kerber, the fast-rising German star who eliminated Williams at the Olympics.

Novak Djokovic shares a heartwarming moment with a young fan (screengrab via YouTube)

Novak Djokovic was in the midst of a routine U.S. Open practice session on Sunday when a boy in the stands interrupted with what had to be the last question the Serbian tennis star expected to hear

"Djokovic, will you marry me?" the boy jokingly shouted.

A marriage proposal from a male voice caught Djokovic by surprise enough that he peered into the stands to see if he could determine the source. The boy then ran down the steps to the railing along the court, which elicited a chuckle from both Djokovic and the rest of the crowd that had gathered.

Djokovic could have easily ended the moment there and returned to his practice session, but what he did instead shows why he's among the more beloved players in men's tennis. Ever the showman, Djokovic invited the young fan onto the court, handed him a racquet and allowed him to take a few serves.

Skeptics on the Internet are already claiming the moment was staged, and perhaps it was considering the video quality and camera work seems a little too perfect. Regardless, this is still a heartwarming moment.

At best, it's an example of the spontaneity and generosity of a man who has won five grand slams at age 25. At worst, it's a publicity stunt that still enabled a young fan to meet his idol on one of tennis' most famous courts.

The joy the boy showed at having that opportunity is something that can't be faked.

When a reporter asked Serena Williams on Saturday about the controversy surrounding the "Crip Walk" dance she performed after winning gold at the Olympics this month, she expertly brushed off the question by claiming she reads "zero press."

Only after a follow-up question later in her pre-U.S. Open news conference did Williams truly lose her temper.

Asked if she regretted celebrating with a dance made famous by gang members from her hometown of Compton decades ago,  Williams insisted she wasn't familiar with the back story. Her response is at the 4:26 mark of the above video, which is a tad quiet and may require the volume to be cranked up to hear.

"First of all, it was just a dance," she said. "I didn't know that's what it was called. Second, why are you asking me that? Like that's so — I mean — if anything you should be trying to ask me questions to lift me up, not bring such things. I'm done with that question."

Before addressing Williams' snippy response, it's important to note that the initial uproar over her shout-out to her hometown was probably overblown. Maybe it was a little bit inappropriate to celebrate a gold medal with something associated with gang culture, but Williams' dance was certainly not glorifying or endorsing that lifestyle.

Nonetheless, that doesn't excuse Williams' habit of telling fibs during her press conferences.

If you didn't know it by now, Venus and Serena Williams are in pretty decent shape. When you have a combined 21 Grand Slam titles, you must be doing something right. And for the Williams sisters, that apparently means spending countless hours hitting the court and gym on a regular basis.

Here's a shocker: Venus and Serena Williams are in really good shape. — New York Times

Earlier this week, Busted Racquet highlighted Serena Williams' physique, after she showed up to the "Late Show with David Letterman" wearing a form-fitting red dress that had Letterman saying things that ... well, here's the actual quote from the show following Williams' entrance.

"I think I saw your eyes almost pop out there," Williams said.

Responded Letterman, "Well, I think so ... That's not the only thing."

It's hard to believe just six months ago people were claiming Serena was "out of shape." The same could be said for sister Venus, who was diagnosed recently with Sjorgen Syndrome, a disease that causes fatigue and joint pain. Needless to say, she hasn't been able to spend hours grinding away