Serena Williams isn’t playing at the U.S. Open this year, but she may be here in spirit. Last night, Andy Roddick was in the throes of a heated match with Janko Tipsarevic when he was fouled for a foot fault. None too pleased, Roddick demanded to know which foot touched the line. The lineswoman claimed the back foot (something that’s, all told, near impossible), and it sent Roddick into an ugly tirade. He was already being schooled by a surprisingly aggressive opponent, but the ordeal was the final nail in the coffin, irrevocably clouding his focus. Thus: Roddick lost in the U.S. Open’s second round for the first time in his career, in a fashion that suggests his recent progressive leaps to become a better player are still hampered by an issue of mentality, and perhaps maturity.

Players are always irritated by foot faults because they’re calls that can’t be challenged; a tiff is not unusual. But Roddick continued to mutter dissent into the next game, at one point mocking the lineswoman and decrying her a “1-800-Rent-a-Ref.” In his post-match press conference, he claimed that he was only upset by the fact that the she confused his feet and wouldn’t admit her mistake, rather than the fact that a foot fault was called at all. (For what it’s worth, Roddick did fault, but with his front foot.)

If that’s true, Roddick’s tirade was completely derivative and a symptom of a crippling problem. He has a habit of growing increasingly angry about a perceived injustice when he’s not playing well, and while he’s a more complete competitor now than he ever has been, his misguided temper still gets him in trouble.

Regardless of how the controversy affected Roddick, there was no doubt that Tipsarevic was the better player last night. He played high-risk tennis by going for broke with shots with incredible depth, angles, and control. Capitalizing on Roddick’s curious resistance to take command of the point, Tipsarevic hit 66 winners throughout the match. The foot fault wasn’t even called until Roddick was already behind 2-5 in the third set. On-air, John McEnroe mused that perhaps this controversy would fire Roddick up and make him finally start playing more aggressively. But while McEnroe’s famous outbursts made him stronger and more brutally focused, Roddick continued to make poor tactical decisions during rallies that cost him the third set and finally the fourth, in a tiebreak.

For many years, Roddick has solely carried the torch for American men’s tennis as our No. 1 player, so his every defeat inevitably becomes an analogy for the demise of competitive tennis in this country. The media went into fits when he briefly dropped out of the top ten for two weeks this summer — the first time an American wasn’t in the top ten in the history of the ranking system — and a second-round loss on home turf will likely keep the conversation going. However, there’s a silver lining for intensely patriotic fans: Earlier that day a very impressive 18-year-old named Ryan Harrison constructed a solid win over the No. 15 seed, Ivan Ljubicic. He exhibited natural court sense, strategy, and composure, and — in a delightful twist — he became the first American male teenager to oust a top twenty seed at a Slam since (you guessed it) Andy Roddick in 2001.

Immediately after Harrison’s victory yesterday, this tidbit was an amusing bit of trivia. With Roddick’s untimely exit last night, it may become a point of industry fixation.