Dwain Chambers enjoyed the best of times last night in his tale of two trials, and so did Scotland's Olympic aspirants who were in action at the Aviva UK Championships at Birmingham's Alexander Stadium.

Lee McConnell is fastest qualifier for today's 400 metres final (53.43), while her training partner Carey Easton, of City of Edinburgh, kept her Beijing relay prospects alive as third fastest (53.92) running behind McConnell in the same heat.

It proved the worst of times, however, for the World 400 metres silver medallist, Nicola Sanders, who withdrew having felt a tight left quadriceps in warm-up. "Just a precaution," she said, but with world champion Christine Ohuruogu running the 200m, the selection policy is in potential tatters.

If the first two in today's final were to run 51.50 or better, the policy requires them to be selected. This would mean leaving out one of Britain's two World medallists from Osaka last year.

"It was windy, and I just did as much as I had to," said Glasgow's McConnell, who already has the Olympic mark and should now win today. "It's not good, Nicola pulling out. It could complicate things, though if the weather is like this, nobody else is likely to get the qualifying standard."

Former European 100 metres champion Chambers, who is fighting a British Olympic Association bylaw which excludes convicted drug cheats from the selection equation, was fastest first-round qualifier in the men's 100m This three-day event is the official Olympic trial, with the gold and silver medallists in each final guaranteed selection. Chambers looks odds-on to win tonight's final, and hopes Mr Justice Mackay will endorse his attempt to have the BOA rule set aside in a High Court trial on Wednesday.

This would allow him to compete in Beijing, and would be a huge blow to the BOA, one of less than a handful of national Olympic committees worldwide to apply an exclusion policy to convicted cheats.

Chambers lined up alongside Scottish 200m champion Jamie Coull in the very first heat, and blew the Pitreavie athlete away as he finished in 10.14 seconds (wind +1.9). Simeon Williamson (10.31) was second fastest over all the heats, while Tyrone Edgar, just one hundredth slower than Chambers's best time of 10.05 this summer, was poorest of the seven heat winners at 10.54.

Nick Smith, three-times Scottish champion at this distance, was second (10.40) behind defending champion Marlon Devonish (10.38). "I know I can go quicker tomorrow," said the Fifer. "I didn't get the best start, but held Marlon well once I got going."

Despite a slip at the start, Coull logged his fastest time of the season, 10.81, in fourth. "This augurs well for the 200m. That's what this was about. Being drawn next to Chambers meant nothing to me. I'm here to focus on my performance, and have no view about him going to the Olympics."

Chambers claims those athletes with whom he associates are supportive of him. The scanty crowd certainly applauded him, but they were almost outnumbered by the media, which included 10 TV crews - a sadly predictable circus. A relaxed Chambers chatted to them on his arrival.

Afterwards, however, he admitted: "It was tough mentally. Going out first is difficult, but I got the job done, and I'm pleased with the time in these conditions. There's a lot of pressure on me, but I'm blocking it out. There's a lot riding on my performance here. The rest is up to others."

Mr Justice Mackay has been reported as saying that Chambers would pass this Birmingham test with "flying colours". Not a bad judge, on last night's evidence.

"If the crowd support sways the judge, fine," said Chambers. "But in the end what will be will be with the judge, and I'll have to get on with my life. . . but he's obviously a sports fan, and that helps."

Edinburgh's Gillian Kerr upstaged national triple jump record-holder Nony Mordi (13.62m last week) to take Scotland's first medal of the championships, with a wind-assisted 13.03 metres.

It was interesting to note that on the 84th anniversary of Eric Liddell's Paris Olympic victory at 400m, there was still not a Scot to touch him at these championships. Only two of the field ran faster than Liddell's winning 47.6 in 1924. And though two Scots reached the semis today, they were slower than their iconic forebear. Kriss Roberston is sixth fastest at 47.86, and Allan Stuart is also through, with 48.55.