New York: Wimbledon champion Petra Kvitova made an unceremonious exit from the US Open on Monday as Maria Sharapova showed her resilience as she scratched out a three-set first-round victory.

Unheralded Romanian Alexandra Dulgheru, ranked 48th in the world, defeated world number seven and fifth seed Kvitova 7-6 (7/3), 6-3.

Meanwhile Sharapova, who was stunned by Kvitova in the All England final, battled back from a set and a break down to defeat British teenager Heather Watson 3-6, 7-5, 6-3.

It was a another post-Wimbledon disappointment for Kvitova, the 21-year-old Czech who has been unable to build on her Grand Slam breakthrough.

"It's something new for me," Kvitova said of the stresses off carrying the title of Grand Slam champion into a tournament. She has won just two matches since Wimbledon.

Her discomfort showed in 52 unforced errors. Once she started making the mistakes, she said, she let the negativity creep in.
"Everything is in the head," she said. "If you are thinking on court negatively it's bad."

Sharapova, too, had more than her share of mistakes, but her 58 unforced errors -- with eight double faults – were countered by a 41 winners.

Watson, 19, came up with just nine winners and couldn't hold off the former world number one and 2006 US Open champion in the third set.

"In the end, that's kind of where it counts," Sharapova said.

Mardy Fish, making his first Grand Slam start as the top-ranked American, got top billing on the Arthur Ashe court and cruised past Germany's Tobias Kamke 6-2, 6-2, 6-1.

Fish, seeded eighth, needed just an hour and 43 minutes to advance, saving five of six break points he faced. Kamke struggled with his serve, delivering seven double faults as he was broken seven times.

Croatia's 27th seed Marin Cilic brought a quick end to the hopes of another American, Ryan Harrison, beating the 19-year-old 6-2, 7-5, 7-6 (8/6).

Harrison made an immediate impression on his debut here last year when he upset 15th-seeded Ivan Ljubicic -- also of Croatia.
But this time around he couldn't capitalize on opportunities to serve out either the second or third set, and he wasted a 4-1 lead in the tiebreaker.

He was also booed by the home crowd when he skimmed his racquet across the court in frustration after dropping his serve to surrender the second set.

In other early matches, ninth-seeded Czech Tomas Berdych, the 2010 Wimbledon runner-up, defeated French qualifier Romain Jouan 6-2, 7-6 (7/4), 6-1

Berdych, beaten in the first round here in two of the last three years, was delighted to get through.      Second-seeded Vera Zvonareva of Russia, beaten finalist here last year, defeated Stephanie Foretz-Gacon of France, 6-3, 6-0.

Other women's winners included 13th-seeded Peng Shuai of China, who defeated Varvara Lepchenko of the United States 6-3, 6-4, and German 19th seed Julia Goerges, a 6-3, 6-2 winner over compatriot Kristina Barrois.