A sixth-place finish over 1,500 metres in Brussels last night provided Sonia O'Sullivan with another useful test run ahead of next month's Sydney Olympics. Her time of four minutes 4.62 seconds was her second fastest of the season, although once again the depth and quality of Grand Prix races at this distance proved somewhat beyond her range. In a tight finish, O'Sullivan found the closing speed of former world champion Carla Sacramento of Portugal a little too hot to match, the winning time of 4:00.35 her fastest of recent years. The much improved Romanian Violeta Szekely-Beclea was inches behind in 4:00.99, with the Algerian Nouria Benida-Merah third in 4:01.23.

For O'Sullivan, who is coming off a heavy schedule in the last fortnight and is still gearing all her preparations for the 5,000 metres, it is another reassuring test of form. She was in contention throughout the race, but didn't quite have the legs to respond to the acceleration over the last lap.

One of the more surprising athletes to finish ahead of her last night was Sureyya Ayhan of Turkey, who finished fifth in a national record of 4:03.02.

O'Sullivan had indicated that she was eager to match her 4:01.70 time from Oslo last month. Yet with the 800-1,500 metres double at the national championships in Santry last weekend, and the 3,000 metres in Zurich the week before, there was probably a certain element of tiredness carried into this race.

In Gateshead on Monday, she will have a final pre-Olympic test - this time over 3,000 metres - before departing for Sydney. And as stated after the national championships, her sole focus is now on the 5,000 metres in Sydney, although there is still the option of coming back for the 10,000 metres if she desires.

Among the other contenders showing their worth in Brussels, the fifth stop on the Golden League tour, was 100 metres favourite Maurice Green. And it seems he has timed his form perfectly as he clocked 9.88 seconds, the fastest in the world this year. His lesser known countryman Bernard Williams was second (10.01) and Ato Boldon of Trinidad third (10.02).

But other medal prospects will be less satisfied with their form, especially Canada's defending champion Donovan Bailey, who was back in eighth place in 10.20.

Michael Johnson also showed that the disastrous 200 metres at the American trials is well behind him, winning the 400 metres in 44.07. Behind him, Britain's Mark Richardson continues his return in style, clocking 44.72.

Important psychological victories too for Australia's big medal hope Cathy Freeman, who took the 400 metres in 49.78, and of course Marion Jones, still proving unbeatable over the 100 metres (10.83).