Ana rides the Mexican wave

Guevara subsequently won in 50.16 seconds but on July 2 in Rome, Tonique Williams-Darling of the Bahamas ended the world champion8217;s winning streak of 28 successive races, clocking an impressive 49.25 seconds.

Guevara now has one more race in Zurich on August 6 before the big one at the Olympics in Athens.

From January to June, Guevara kept a low profile, trying to avoid talking about repetitive stress injuries to her ankle tendons that prevented her from running, although she trained by swimming.

Her performance in the first six months of 2004 strongly contrasted with last year when the lanky 27-year-old sprinted to a brilliant success story and the press whipped up a national frenzy of expectations.

In 2003, Guevara became world champion by clocking 48.89 seconds in the 400 metres, which still stands as the best pre-Olympic time in the run-up to the 2004 Games.

She holds the eighth position as fastest female 400-metres runner though her personal record is still far from the 47.60s world record set in 1985 by German runner Marita Koch, competing at the time for East Germany.

Despite losing to Williams-Darling, Guevara continues to be the strong favourite to win the gold in Athens. No other runner in her category comes close when she is on form, and certainly there is none in Mexico, where 8220;Guevara8221; is a household name.

Endorsed by a large private bank, posters of the husky-voiced runner are plastered all over the country. She advertises all sorts of products ranging from packaged bread to cellular telephones.

The former basketball player turned runner has also become a role model and an inspiration for Mexican women to break the mould in a traditionally macho society.

Posing for photographers, she likes to flex her biceps in a show of strength, a masculine gesture which is offset by her large hoop earrings and long manicured nails. It took getting used to, but now the fans go wild when she does it.

Guevara is the fastest woman ever in the history of athletics in Mexico and little children hysterically shout 8220;Ana! Ana!8221; whenever she shows up at publicity events.

She is perhaps the most popular woman in Mexico. Sports associations named her the country8217;s best athlete and the best in Latin America last year.

The native of Nogales, Sonora in northern Mexico, laps up the attention playfully. She had a T-shirt especially made with the stamped image of her face replacing that of legendary Latin American revolutionary Ernesto 8220;Che8221; Guevara 8211; the other famous Guevara.

Tall for a Mexican woman, at 1.73 metres, a sports physician has said of Guevara that her physique 8211; her powerful thighs and long legs, well-developed muscles and above-average height 8211; is an asset to her speed.

The man who has subjected her to intense workouts since 1997, her Cuban-born trainer Raul Barreda, has said, 8220;From the start I made Ana Guevara dream with the idea that both of us together would work towards the goal of building a world champion.8221;

For Guevara, there is only one rival 8211; herself. 8220;The challenge is to defeat myself because the worst enemy that one has is the one we carry within,8221; she once said.

gms/dpa