Pressure of season Slam getting to Serena?

— -- LONDON -- Serena Williams is 33 years old, but she's not too old -- or proud -- to cry.

Even as the final point was replayed on a hushed Centre Court, the sobs began. By the time she extended a hand to the vanquished Heather Watson of Great Britain, the tears were brimming in her big brown eyes.

Serena was down 3-love in the third set -- two bloody service breaks -- and yet she found a way to rally famously -- again -- all the way into the fourth round with a 6-2, 4-6, 7-5 victory against Watson.

"I think [Watson] played unbelievable," Serena said in a quavering voice. "She should have won the match -- she was up two breaks. She was just playing so good, there was nothing I could do."

At the French Open, Serena contrived to lose the first set four times -- and rallied each time to win. Five of her matches on the way to the title went the three-set distance.

The fact is, Serena keeps putting herself in difficult positions and always seems to wiggle out.

"I honestly didn't think I was going to win." Serena said in her postmatch news conference. "I honestly thought I was going to lose. I thought maybe it just wasn't my day.

"I was thinking I might take a dance class or go see Venus play [on Monday]."

Long ago, in a galaxy far away, Serena won the last three Grand Slam singles titles of 2002. When she added the 2003 Australian Open to her shopping cart, Serena held all four major trophies.

This was remarkable because it hadn't happened in 15 years, when Steffi Graf won a calendar-year Grand Slam in 1988. On the men's side, you had to go back to Rod Laver's Slam in 1969.

Serena was testy when a Grand Slam question surfaced early in the news conference.

"I'm not going to answer any more questions about the Grand Slam, the alleged Serena Slam," she said.

Last year here at Wimbledon, Serena lost ignominiously in both singles and doubles. First there was an inexplicable third-round loss to Alize Cornet, then a curiously troubling woozy and premature departure in doubles that raised all kinds of questions.

Serena has lived fabulously but dangerously since then; she has gotten startlingly close to the precipice, as evidenced in her match against Watson on Friday.

At 3-all in the third, as the set lurched wildly to its conclusion, the atmosphere on Centre Court was charged as they tried to carry their player, Watson, to victory.

At 6-5, Serena carved out a match point, but she blasted a forehand service return into the net. The same thing happened again on the second match point.

On the third, however, she sent a whistling shot that grazed the baseline. Watson could not come up with a swinging backhand half-volley. When the replay confirmed it was good, Serena had escaped again.

A dozen years after she won those four straight Slams, Serena still finds herself in a position to do it again. Since that low-water mark at Wimbledon, Serena had been a perfect 23-0 in Grand Slams matches.

No good deed goes unpunished, however, and now she will have the awkward task of playing older sister Venus on Monday.

"She's in better form than I am, so I think she has a little bit of an advantage," Serena said. "At least one of us will be in the quarterfinals."

Serena called her match against Watson the toughest one she's ever played on Centre Court.

Just wait until Monday.