Among the many lessons Serena Williams has learned in the 13 years since she played her first Grand Slam final is that routine is overrated.

A perfect attitude to bring into the U.S. Open final, where the only consistent thing over the past five years has been that very little goes according to schedule.

This year, the women's final between Williams and Victoria Azarenka was pushed back a day because of a strong storm bearing down on New York. It marks the fourth time in the last five years the women's final, normally scheduled for Saturday, will be played on Sunday instead.

All of which is fine for Williams, who has been in the mix for three of those finals, and said she's become much better at going with the flow over the years.

"I have really gotten out of being so into routines because it can really drive someone bananas," Williams said. "I've been on the verge of going bananas because I have to have this, this, this. It wasn't helping me win. It wasn't helping me lose. It has nothing to do with that. I have kind of chilled off on that."

Whatever she's doing is working. The 30-year-old, 14-time Grand Slam titlist is in the middle of a summer that will certainly stand out, even by her standards:

— Winner at Wimbledon and the London Olympics in both singles and doubles.

— Finalist at the U.S. Open, losing only 19 games and not a single set along the way.

— A win away from capturing her fourth U.S. Open crown and becoming the first 30-something woman to win it all at Flushing Meadows since Martina Navratilova in 1987.

"It will be up there," Williams said. "Because if you win the Olympics and Wimbledon and this, it would be kind of cool."

Also enjoying a pretty cool year is Azarenka, who opened 2012 with the Australian Open title, vaulted to No. 1 in the rankings the next week and will stay there regardless of who wins Sunday. Williams said she comes into the match with nothing to lose because she's playing the best player on tour this year.

"I always believe that I'm the best, obviously," Williams said. "But I mean, on paper, I think she's been more consistent."

The rankings say that's true, but they only tell so much, especially over the past two weeks in Queens. While Williams has steamrolled through this tournament, Azarenka has faced a couple of difficult challenges.

To get to the final, she needed back-to-back three-set wins over defending champion Sam Stosur and French Open titlist Maria Sharapova. Those two matches took a combined 5 hours, 5 minutes — only 92 minutes less than Williams has been on the court over the entire tournament.

Azarenka is 1-9 lifetime against Williams, with her only victory coming more than three years ago in Miami. More recently, she lost 6-3, 7-6 (6) in the Wimbledon semifinals, then 6-1, 6-2 in the semifinals at the Olympics.

"When I go to play against her, I don't think that I'm playing against Serena," Azarenka said. "I just try to go the same way and try to focus more on myself. But you definitely know that it's going to be big adversity there on the court against you. You have to be prepared to make sure you want to dig deep and accept the challenge."

Last year, rain reshuffled the schedule at Flushing Meadows and Williams was on the court until around 11:30 p.m. Saturday for her semifinal win over Caroline Wozniacki, then forced to make a quick turnaround for the final Sunday afternoon.

She went into that final after another dominating roll through Flushing Meadows, losing only 29 games over six matches. Many figured her showdown against Stosur, who went a grueling three sets in her semifinal victory, would be a mere formality.

Turned out it was. For Stosur. Williams got into an argument with the chair umpire — "You're a hater, and you're just unattractive inside," she said — and ended up losing 6-2, 6-3.

But given all she had been through that year — the cuts on her feet from glass at a restaurant, two foot operations, clots in her lungs — she said it was hard to be too upset with a trip to the U.S. Open final.

"I mean, I was definitely disappointed, but not as down as I would have normally been under any other situation," she said. "This year, I'm physically better. I'm more confident, playing more matches and winning. I have Wimbledon under my belt."

If she wins Sunday, she'll remain the only woman to win more than one Grand Slam tournament in a single year since 2007 (Justine Henin).

If Azarenka wins, she'll become the first woman to accomplish that since Williams last did it in 2010.

When her win over Sharapova was over, Azarenka said she wished she could stay on the court and keep playing. Instead, she'll walk on with about 48 hours of rest. That's two days to think about how to take down a champion.

"If you look at our record, it says it all," Azarenka said. "I mean, I haven't won in any last meetings, so I definitely need to find something to surprise her ... because she's in a great form, feeling really confident right now.

"You know, she has everything on her side."