NEW YORK (AP) -- Melanie Oudin's face was flushed from a mix of exertion and excitement and maybe even a bit of bewilderment -- "Yes, I DID beat Maria Sharapova!" running through her mind -- when she stepped out of the U.S. Open locker room and saw Mom.
The pair embraced, kissed each other on the cheek, and Leslie Oudin told her 17-year-old daughter: "I'm very proud of you." Then they hugged some more, holding tight.
Melanie Oudin is still very much a kid from Marietta, Ga., enjoying the trip of her life in the Big Apple, playing foosball in the players' lounge and using words like "amazing" and "cool" as she works her dizzying way through the draw at Flushing Meadows. Oudin's latest win was the biggest so far: She knocked off three-time Grand Slam champion and former No. 1 Sharapova 3-6, 6-4, 7-5 Saturday to reach the U.S. Open's fourth round.
"I just had a blast," said Oudin, who buried her face in a towel and sobbed on the sideline when the match ended.
Several hours later, on the same court, another unheralded American pulled off another upset of a past U.S. Open champion: 55th-ranked John Isner pounded 38 aces and eliminated No. 5 Andy Roddick 7-6 (3), 6-3, 3-6, 5-7, 7-6 (5) to reach the fourth round at a major tournament for the first time.
Roddick is the first of the top 16 men to lose this week. He won the 2003 Open and came oh-so-close to winning Wimbledon in July, but he now must resume his pursuit of a second career major title next year.
Instead, it's the 6-foot-9 Isner who moves on, thanks to some outstanding serving and success at the net: He won 42 of 67 points when he pushed forward.
Sharapova, it bears noting, double-faulted 21 times, the most by a woman in any 2009 tour match. But the 5-foot-6 Oudin's solid groundstrokes and tremendous court coverage -- all those small, squeaky steps -- and veteran-like presence played significant roles, too.
So, perhaps, did the partisan fans, who began hootin' and hollerin' to celebrate their girl's victory right as her racket met the ball on the clinching forehand winner.
"I try to pretend that it's not, like, Arthur Ashe Stadium, playing Maria Sharapova. I try to just pretend it's any other match -- even just practicing. Sometimes I tell myself I'm just practicing at my academy at home, and I'm just playing one of my friends," Oudin said. "So it's not a big deal."
Oh, it most certainly is a big deal.
A year ago, Oudin was ranked 221st and lost in the first round in New York. Now she is 70th -- steadily moving up -- and the youngest American woman in the U.S. Open's final 16 since Serena Williams a decade ago.
"Her first goal was to get into the tournament," Oudin's coach, Brian de Villiers said, "and the second one was to win a round here."
Check. Check. And then some, including a second-round upset of No. 4 Elena Dementieva, a two-time Grand Slam finalist and the Beijing Olympics gold medalist.
Nothing happening around the tournament grounds on a busy Saturday afternoon matched the buzz of Oudin-Sharapova, although that would have changed had 276th-ranked Jesse Witten of Naples, Fla., managed to pull off a similar stunner against No. 4 Novak Djokovic.
Witten won one set, and had chances to take another, before losing 6-7 (2), 6-3, 7-6 (2), 6-3.
"I wasn't getting outplayed too much," said Witten, 0-6 in tour-level matches before this week. "I felt like I was right at home a little bit."
Before Roddick's loss, the top 16 men in the tournament were a combined 38-0. Leading the way was No. 1 Roger Federer, who overcame a sloppy first set and tumble to the court to beat two-time major champion Lleyton Hewitt 4-6, 6-3, 7-5, 6-4.
Federer has won 14 consecutive matches against Hewitt, and 37 in a row at Flushing Meadows.
"I knew that being down a set against Lleyton is always going to be a difficult situation for me to be in: Make one more mistake and I'm in the fifth set, maybe, or I go down completely," said Federer, trying to become the first man since the 1920s to win the American Grand Slam tournament six consecutive years. "So I was relieved coming through."
Also into the fourth round: No. 8 Nikolay Davydenko, No. 10 Fernando Verdasco and French Open runner-up Robin Soderling, who beat No. 22 Sam Querrey of the United States 6-2, 7-5, 6-7 (6), 6-1.
Oudin has done this sort of thing before. Well, once before: She got to Wimbledon's fourth round this year by defeating former No. 1 Jelena Jankovic. After that match, Jankovic harrumphed that Oudin "cannot hurt you with anything; she doesn't have any weapons."
Sharapova disagreed. The 2006 U.S. Open champion was seeded 29th and has yet to fully rebuild her game after shoulder surgery in October, yet is far more experienced in these kinds of matters.
"Got to hand it to her," Sharapova said. "She really stuck to her game plan. She played solid. She made me hit a lot of balls."
Sharapova missed the mark plenty, compiling 63 unforced errors, 19 more than Oudin. All those double-faults, several at key moments, helped Oudin compile an astounding 26 break points -- and she converted eight.
Oudin is 8 inches shorter than the 6-2 Sharapova -- "You know, I sat out there thinking, 'Oh, my gosh, compared to Sharapova, she looks so tiny out there," Leslie Oudin said -- but traded booming groundstrokes from the baseline.
"I can compete with these top girls," Melanie Oudin said. "And if I believe in myself, and my game, then I can beat them."
She's wearing pink-and-yellow sneakers with the word "BELIEVE" stamped near the heel -- it was her boyfriend's idea -- and that mantra clearly has served Oudin well.
It wasn't all that long ago that Sharapova was the up-and-comer, the 17-year-old who won Wimbledon, then tried to make a cell phone call to Mom right there on Centre Court.
So heed Sharapova's words when she says of Oudin: "I certainly think she has a great future ahead of her."
Oudin now faces a fourth consecutive Russian ranked higher than she is: No. 13 Nadia Petrova.
"The funny thing is," de Villiers said, "when the draw came out, I said to her: 'You realize, to win this tournament, you're going to have to beat six Russians and a Williams."
Must have been a tongue-in-cheek comment at the time, but who would doubt Melanie Oudin of Marietta, Ga., now?
(Copyright 2009 by The Associated Press. All Rights Reserved.)