UPDATE 3-Olympics-Romanian Tomescu dominates marathon

(Updates with detail, quotes)

By Balazs Koranyi

BEIJING, Aug 17 (Reuters) - Romania's Constantina Tomescu won the women's Olympic marathon with a dominant solo run from the halfway point on Sunday.

The 38-year-old made her move after a large leading group set a plodding early pace and, with nobody choosing to respond, was a minute clear inside the final 10km.

Pre-race favourite Catherine Ndereba of Kenya beat China's Zhou Chunxiu for silver in a down-to-the-wire sprint as around 50,000 patiently-waiting fans cheered the home favourite.

Tomescu, third in the 2005 world championships and world half marathon champion the same year, stretched her lead further over the closing stages to win in two hours, 26 minutes 44 seconds.

"It was a great performance. At the world (half marathon) championships in Canada, everybody said I couldn't run, but I showed today what I can do," Tomescu told reporters.

COOL TEMPERATURES

Beijing's notoriously muggy weather relented with cool temperatures, an overcast sky and occasional drizzle keeping conditions bearable.

World champion Ndereba, silver medallist four years ago, showed little sign of life in the first part of the race.

She hit the halfway mark in 26th place and briefly faded from the pack only to gather speed again in the closing stages and finish in 2:27.06, a second ahead of Zhou.

Kenya, who have dominated the marathon for decades, have never won Olympic gold in the women's event.

"I got the silver and I'm not disappointed -- disappointed isn't in my vocabulary," Ndereba said "She (Tomescu) just disappeared from us.

Zhou had the consolation of China's first Olympic marathon medal.

"I think everybody in China was hoping I'd win a gold medal," Zhou said. "But I have done what I can. I feel a little sorry but I gave it all my potential."

Paula Radcliffe, Britain's world record holder, was dropped from the chasing pack just past the 30km mark and was clearly not in top form after spending weeks nursing a thigh injury.