Five things we learned from the Big Five matches

Ravi Ubha is providing instant analysis of each one of Tuesday's Big Five matches -- which feature Elena Dementieva, Novak Djokovic, Roger Federer, Jelena Jankovic and Andy Roddick -- all day. Come back for the latest.

1. The women's game could use more depth: Remember what happened to frustrating lefty Patty Schnyder at the French Open last year? She blew two match points against Maria Sharapova in the fourth round, eventually losing 9-7 in the third.

Afterward, she called Sharapova a "big" champion and herself a "little one."

There was more evidence of that Tuesday in Schnyder's 6-2, 6-3 loss to fifth-seed Elena Dementieva. Appearing in her second major quarterfinal in 10 years outside Australia, the veteran Swiss barely put up a fight.

Thank goodness it was the first match at Arthur Ashe Stadium, with many seats empty.

The encounter lasted 1 hour, 16 minutes, the only drama surfacing when Schnyder broke back to make it 3-3 in the second. Sure, Dementieva is on a roll, but Schnyder trailed their head-to-heads by a respectable 9-7 margin.

Schnyder, coached by her husband Rainer Hofmann, made 29 unforced errors.

Dementieva's double-fault woes from earlier in her career are well-documented, but on Tuesday she won 79 percent of points behind her first delivery and committed just one double fault.

2. Novak can't help but hurt himself: What body part will Novak Djokovic injure next?

Djokovic endured another physical nightmare at this year's tournament, hurting his right hip and right ankle in a dramatic 4-6, 6-2, 6-3, 5-7, 6-3 win over gung-ho Spaniard Tommy Robredo.

As if that wasn't enough, Djokovic apparently came down with an upset stomach, perhaps a result of taking painkillers for the hip problem.

The hip malaise arose early in the second set following a baseline rally; Djokovic had cream and tape applied. Late in the fourth set, Djokovic rolled the ankle, though he was lucky it wasn't severe.

He must have seen this coming.

In a first-round triumph over plucky French veteran Arnaud Clement, the 21-year-old turned his left ankle. In his next encounter, against big-serving American qualifier Robert Kendrick, Djokovic hit the turf after he unleashed a backhand.

At least Djokovic can turn to his compatriots for sympathy.

Ana Ivanovic, waiting to be deposed as the world No. 1, only recently returned from a thumb injury and went out early in New York. Jelena Jankovic's latest ailment was a calf strain, and the inconsistent Janko Tipsarevic retired in the first round with an ankle injury.

"If I start talking about the things that are bothering me now, we can talk until tomorrow," Djokovic said in a courtside interview.

3. Federer is pumped: Roger Federer, dethroned at Wimbledon and in danger of failing to win a Grand Slam title in a season for the first time since 2002, isn't relinquishing his U.S. Open crown without a fight.

Federer showed more emotion than fans are used to seeing in his gripping 6-7 (5), 7-6 (5), 6-3, 3-6, 6-3 win over Russian Igor Andreev, who put up stiffer resistance than anticipated, helped largely by his thundering forehand.

The turning point of the fifth came when Federer broke for a 3-1 advantage. And what a point it was to break.

Andreev came forward chasing a short ball, having plenty of time with Federer out of position, and decided to play a drop shot. It seemed like the wrong option.

Federer, whose movement is often underrated (he has a few other weapons), indeed got there in time and pushed his reply deep in the court. Andreev backtracked and spun, but sent a backhand wide.

Federer, looking like the Incredible Hulk, celebrated in style. He enacted a similar pose when the 3-hour, 32-minute match ended, soon turning and looking to his box, a smile in tow.

"You always wish three sets, but honestly, those five setters are pretty fun, too," Federer said in a courtside interview.

The key stat? Andreev went 2-for-15 on break points, including 0-for-7 in the second set. Federer was 3-for-7 overall and delivered 67 winners, seven more than his unforced error tally.

"If I could make break, like early in the second set, then for sure, I'll have more chances," Andreev said.

4. Things are getting easier for Jankovic: What's this, a straight-sets match involving Jelena Jankovic? Yes, it happened against Austrian mom Sybille Bammer.

Jankovic, believe it or not, has won twice in straight sets in her past three rounds.

The world No. 2 didn't need to be dominant against lefty Bammer, the 29th seed. Despite the comfortable 6-1, 6-4 score, Jankovic was broken four times. She also made 14 unforced errors, double her winners count.

"I got the job done," Jankovic said. "That's the most important thing."

As you might have guessed, Bammer, in her first major quarterfinal, was far worse. She made 40 unforced errors and conceded serve eight times.

Jankovic should enjoy this one. Based on current form, she'll be the underdog against Dementieva in the semifinals, despite leading their head-to-heads 4-3.

5. A few fans got shortchanged: Fans showing up for the night session Tuesday were greeted by a nasty surprise. Due to the length of Djokovic's and Federer's five-set matches, organizers moved the first singles encounter, featuring Jankovic and Bammer, from Arthur Ashe to Louis Armstrong stadium.

That might have been OK if Andy Roddick's tilt with Fernando Gonzalez turned out to be a nailbiter. Gonzalez, though, appeared to be in one of those moods, and meekly exited 6-2, 6-4, 6-1 in under an hour and a half.

The Chilean, now 1-6 in his past seven matches against Roddick, only won about two points per game. Roddick, continuing to flourish under temporary coach Patrick McEnroe, claimed an astounding 93 percent of points behind his first serve.

Given his form and Djokovic's physical frailties, he must be somewhat confident ahead of their quarterfinal. Roddick also downed Djokovic the last time they met, at the Dubai Tennis Championships in the spring.

Ravi Ubha is a frequent contributor to ESPN.com.