Sometimes, even your best isn't good enough.

Eilidh Child scythed another two-tenths of a second from her own Scottish 400 metres hurdles record at the Diamond League in Birmingham yesterday but her time of 54.22 seconds was still only quick enough to claim second place. As has become almost habitual, it was Perri Shakes-Drayton who emerged ahead in their ongoing private battle for supremacy.

If the pair continue to push each other to new heights, it could pay dividends when both reach the world championships in Moscow. The Londoner, who edged Child into silver at the European Indoor Championships in March, has matched the Scot's own improvements but both claimed notable scalps, including Romania's Angela Morosanu.

For Child, her performances here and in Gateshead nine days ago bode well. "It wasn't as smooth as that race, so it's good that the speed is there and I can still run quickly without getting it right," she said. "Hopefully, when it all comes together, I can be even faster than that. These are the sort of girls I need to beat to get into that world championship final, so it's good to get out there and put a marker down. Worlds is the target."

Mo Farah also has Russia on his mind, and the defence of the 5000m title he claimed in Daegu two years ago. The double Olympic champion has been in uncertain form but he doggedly matched Ethiopia's Yenew Alamirew in a two-way duel on the final lap before pulling away at the last.

"It was important that I won the race," Farah said. "The conditions were tough. It was a tough field, so I'm really pleased I came through it with a victory. It's important that I keep working hard now and get ready for the world championships."

Another Olympic gold medallist, Greg Rutherford, was second in the long jump, behind Russia's Aleksandr Menkov, but there was a troubling show from world champion Dai Greene with the Welshman just fifth in the 400m hurdles.

However, there were signs of promise for 2008 Olympic champion Christine Ohuruogu, who was resolute in taking victory in the 400m, overhauling rankings leader Amantle Montsho over the last few metres. "I can't complain with how things are going," she said. "Work is being done."

Teenager Jessica Judd broke through the two-minute barrier for the first time to usurp Marilyn Okoro and win the 800m with a performance that should give European champion Lynsey Sharp cause for thought when she returns from injury.

Laura Muir was eighth in the 1500m in a new personal best of 4:07.76, but fellow-Scot Chris O'Hare rued a chance squandered to make an impact after missing out on the qualifying standard for Moscow in coming eighth in the 1500m.

"I'm not very happy," he said. "I came in to get at least the B stan-dard and I didn't get that, so it's pretty rubbish. I'll have to go home from here and figure it out."

Scotland's Lennie Waite finished 10th in the 3000m steeplechase in a time of 10:06.73.