NEW YORK: Fourth seed Elena Dementieva and fifth seed Jelena Jankovic were upset victims Thursday at the US Open while top-ranked Dinara Safina struggled but is now the only seed still in her quarter of the draw.

Russian stars Maria Sharapova and Svetlana Kuznetsova avoided the trend of shockers and breezed into the third round, but could feel the stress as Flushing Meadows favorites began to fall at Arthur Ashe Stadium.

"You do sense it," Sharapova said. "I saw some of the tough matches. You dont want to be that person."

US teen Melanie Oudin shrugged off a sore left leg to stun 2004 US Open runner-up Dementieva 5-7, 6-4, 6-3, and leave the Russian still searching for her first Grand Slam crown.

"For sure it was disappointing. I was hoping to play very well," Dementieva said. "She had a very good answer to me on the court. She was really playing at her best."

It was the earliest US Open exit by the Russian since 2002, sent off by a 17-year-old American with "believe" written on her pink and yellow shoes.

"I just played with no fear," Oudin said. "I just went out there and played my game and I came out with a win."

Yaroslava Shvedova, a 20-year-old Kazak ranked 55th in the world, outlasted former world number one Jankovic 6-3, 6-7 (4/7), 7-6 (8/6). The 2008 US Open runner-up blew two match points and lost to a Shvedova ace on match point.

"It was great," Shvedova said. "I'm happy so much to be able to beat a great player in the big stadium."

After the match, the Serbian star said she was mourning the death of her grandmother Wednesday night and unable to focus.

"My head wasn't really there. It was like a shadow of myself," Jankovic said. "I tried to think about my tennis but I felt like I was so late and so slow. I was really suffering.

"There are more important things in life than tennis. When you think about it, this is just a small event compared to somebody in your family who dies."

Top seed Safina, seeking her first Slam title, rallied to beat 67th-ranked German Kristina Barrois 6-7 (5/7), 6-2, 6-3. The Russian made 38 unforced errors and double faulted 15 times but endured a roller-coaster day to advance.

As in a first-round narrow escape against Australian teen Olivia Rogowska, Safina lost the first set and went down an early break in the third.

"Another tough day at the office," Safina said. "I don't want to play three sets. Don't think I want to lose the first set, be down a break in the third and fight through. I have to be more disciplined. I will work on it."

French Open champion Kuznetsova, the top remaining seed in her quarter of the draw, routed Latvia's Anastasija Sevastova 6-4, 6-2. The sixth seed whose other Slam crown came at the 2004 US Open never faced a break point.

Sharapova, a former world number one back after right shoulder surgery, beat US teen Christina McHale 6-2, 6-1, and faces another US teen, Oudin, next.

"At 22, you feel like you should be retired," Sharapova said. "That's the sad truth."

Oudin, ranked 70th, had her left thigh taped early in the third set but ignored the pain to finish off Dementieva with a service winner on her third match point after two hours and 45 minutes.

"Going into that last point I was thinking I might not get another chance so I just had to go for it with a big serve," Oudin said. "I was lucky it went in."

Oudin ranked her latest stunner above her third-round upset of Jankovic at Wimbledon.

"This was pretty big," Oudin said. "I think it means more to me since it was the US Open, the crowd was cheering for me and I was struggling with my leg. The whole thing was so amazing."

Safina battled through to a third-round meeting with 72nd-ranked Czech Petra Kvitova, who ousted Italy's 58th-ranked Tathiana Garbin 6-1, 6-3.

Six of eight higher-ranked players lost in Safina's section, the last of them 23rd-seeded Sabine Lisicki, who left the court in tears and a wheelchair.

Aussie qualifier Anastasia Rodionova ousted Lisicki 6-3, 3-6, 7-5 but the German twisted her left ankle on the final swing of the match and crumpled to the court screaming in pain. She was wheeled off still wiping her eyes.

Safina did nothing to silence critics who say Serena Williams is the top player today.

Second seed Williams, the Australian Open and Wimbledon champion, continues her quest for a 12th Slam crown and second US Open title in a row Friday in a third-round match against Spain's Maria Jose Martinez Sanchez while third seed sister Venus meets Slovakia's Magdalena Rybarikova.