ATHLETICS: In the first real step of her marathon countdown Sonia O'Sullivan yesterday switched to the roads and ran the second fastest 5km in history - missing the world best by just two seconds. As a pointer towards her targets of the coming months it couldn't have been more encouraging.

The victory came close to her London home at the Flora Light 5km Challenge, a charity orientated event around Hyde Park that involved 25,000 women. Up front there was also an elite field that included two former London marathon winners and O'Sullivan's latest rival, Marta Dominguez of Spain.

On the day no one could surpass O'Sullivan's pace. From the gun she took out the running and though well tested in the closing stages, she took the win in 14 minutes 56 seconds - just outside the road world best of 14:54 set by American Deena Drossin is Carlsbad, California, last April.

Perhaps more significantly, O'Sullivan's time improved by one second Paula Radcliffe's course record of 14:57, set last year and at the time equalling the world best of Scotland's Liz McColgan.

O'Sullivan's focus on the marathon, almost certain to be in New York in November, is clearly serious from the start.

By pressing the early pace O'Sullivan had at one point around halfway established a 50-metre lead. The chasing group of Dominguez and two Australians, Suzy Power and Benita Johnson, closed up in the final kilometre, and O'Sullivan's hopes of victory looked threatened. Yet she quickened again so that only Johnson stayed in contention, before she too was outpaced in the final stretch.

"I was after the record but I knew I was slowing," said O'Sullivan. "The first kilometre was probably too fast. But when they caught me, just winning the race was the most important thing."

In taking second, Johnson ran a lifetime best of 14:59. Dominguez took third in 15:11 - her third defeat to O'Sullivan since the European Championship 5,000 metres last month. Power was fourth in 15:15, with the two former London marathon winners, Joyce Chepchumba and Tegla Loroupe, both of Kenya, taking fifth (15:24) and sixth (15:26) respectively.

With her training now geared towards the 26.2-mile distance, O'Sullivan, with her typical enthusiasm, then ran some 12 miles home after the race. She competes over 10 miles at the Great South Run in Portsmouth next Sunday before taking on a half marathon at the Great North Run in Newcastle on October 6th.

Also encouraging for O'Sullivan is the fact that she trained heavily in the days before the race. "The idea was to train very hard last week and make this race a test," said her coach, Alan Storey.