His match, and his retirement, put off for at least another day, Andy Roddick stepped out of Arthur Ashe Stadium and into the drizzly night, a black jacket's hood pulled overhead, a bag of ice soothing his right shoulder.

He'll try to prolong his U.S. Open — and his professional tennis career — on Wednesday.

Roddick's fourth-round showdown against another past champion at Flushing Meadows, Juan Martin del Potro of Argentina, was suspended because of rain Tuesday night, with the American leading 1-0 in a first-set tiebreaker.

A little more than a half-hour later, the players were told they could head to their hotels.

They were scheduled to resume Wednesday as the second match in Ashe, after four-time major champion Maria Sharapova's quarterfinal against 2007 Wimbledon runner-up Marion Bartoli. That was halted Tuesday with Bartoli ahead 4-0.

Other matches stopped in progress, also in the first set, included defending champion Novak Djokovic against No. 18 Stanislas Wawrinka, and No. 8 Janko Tipsarevic against No. 19 Philipp Kohlschreiber.

On a day of off-and-on action because of intermittent showers, only two singles matches were completed: Top-seeded Victoria Azarenka reached her first U.S. Open semifinal by cobbling together a 6-1, 4-6, 7-6 (5) victory over defending champion Sam Stosur, and No. 4 David Ferrer reached the quarterfinals by beating No. 13 Richard Gasquet 7-5, 7-6 (2), 6-4.

So, Victoria, what went through your mind as your high-tension, high-quality match stretched into that third-set tiebreaker?

"You don't want to know what I kept telling myself," Azarenka deadpanned. "I would have to beep that, I think."

She went on to offer a cleaned-up version of what her thoughts had been — "Don't be a chicken" — while assuring herself of retaining the No. 1 ranking no matter what happens the rest of this week.

"Definitely I don't want to stop. I really want it bad," Azarenka said about the prospect of adding a second Grand Slam trophy to the one she earned in January at the Australian Open. "I'm going to do absolutely everything I have, you know, to give it all here."

Her match, like most at Flushing Meadows so far, took second billing to one involving the 20th-seeded Roddick, who surprisingly announced last week that this tournament would be the last of his career.

Since then, he picked up victories over players ranked 43rd and 59th, but the No. 7-seeded del Potro figured to provide more of a challenge. Del Potro is the only man other than Roger Federer, Rafael Nadal or Djokovic to win any of the past 30 Grand Slam titles.

There were thousands of empty blue seats when Roddick and del Potro took to the court, probably owing to the showers that led to about an hour's delay at the start of the marquee match. It was hardly the full house of rowdy, partisan fans that Roddick might have hoped for.

More spectators filed in as things progressed, and those who were there certainly grabbed each and every opportunity to cheer for their man.

They even gave del Potro a bit of a hard time when he had a couple of ball boys go wipe a wet spot near the baseline with white towels.

It was misty at the outset, and the humidity topped 80 percent, leaving both men's shirts sopped with sweat.

Roddick came out the aggressor, looking for any opportunity to get to the net, and the volley he smacked to end the third game glanced off the 6-foot-6 del Potro's right shoulder.

Not much later, Roddick nosed ahead, breaking for a 4-2 lead and shaking his right fist vigorously when del Potro flubbed a backhand into the net.

Roddick held for 5-2, saving a break point along the way and showing off quite a varied repertoire: an ace, a drop-shot winner, a backhand winner down the line and an inside-out forehand passing shot.

Seemingly in control, Roddick suddenly slowed, and del Potro finally began showing off the big, flat forehand that carried him past Federer in the 2009 U.S. Open final.

Del Potro pounded one forehand so hard that Roddick shanked an attempted reply off his racket handle, sending the ball into the fourth row of the stands behind him.

It was a rough 15 minutes for the crowd favorite, who five times stood two points from claiming the set, but couldn't get closer. When Roddick served for it at 5-3, he played a loose game, rolling his eyes after putting one backhand into the net, then sailing an approach shot long and rushing a forehand long. Del Potro broke there and eventually, as drops began to fall, they headed to the tiebreaker.

After only one point, an inside-out forehand winner by Roddick, chair umpire Carlos Bernardes stepped down to inspect the wet court and declared it unplayable. A few spectators booed. Roddick and del Potro sat in their changeover chairs for a few minutes, until being told the delay would be substantial enough that they could wait it out in the locker room.

Not much after that, they found out they would need to come back Wednesday, when the forecast calls for an 80 percent chance of rain.

Azarenka and Stosur needed to wait out a 75-minute delay in their first set, but at least they got done.

Stosur never had taken so much as a set off Azarenka in six previous tour meetings, including one match in qualifying. That changed in Tuesday's second set, although forcing a third might not have given Stosur all that much self-belief. And in the end, Azarenka improved to 11-0 in three-setters this season, while Stosur fell to 9-7.

"I think I'm capable of beating her one day," the seventh-seeded Stosur said. "Just would have liked it to have been today."

Serving at 5-all in the third, Azarenka faced a break point and responded the best way possible, delivering a 92 mph ace, her only one of the match.

Asked about that at her news conference, Azarenka's response was telling: "When did I hit an ace? Did I hit one today, actually?"

Her serve is not exactly her strongest stroke, and Azarenka double-faulted five times, including while ahead 5-3 in the tiebreaker.

Azarenka used a swear word at her news conference to describe the second fault there, which landed several feet long. That was part of a topsy-turvy tiebreaker, in which Azarenka went ahead 4-0, and Stosur took five of the next six points to make it 5-5.

That's when Azarenka buckled down.

"For sure, she really pushed me to dig deep," Azarenka said.

On the next point, a Stosur groundstroke clipped the net and went over, and Azarenka had the presence of mind, and soft hands, to respond with a drop-shot winner. That set up match point, which fittingly was a hit-'em-hard, 10-stroke exchange, until Stosur sailed a backhand long.

Azarenka dropped her racket, put her hands to her face, then looked skyward and said, "Oh, my God."

She went to the middle of the court and raised her right index finger overhead — yes, she's No. 1 in the rankings, and she'll stay there for the time being — before blowing kisses to the crowd and throwing a ball into the stands.

She said later she was unaware that her victory locked up that top spot, and explained that a U.S. Open trophy would mean a lot more.


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