BOSTON - Reigning world champion Shawn Johnson showed she's still the one to beat, taking a solid lead at the U.S. gymnastics championships last night with a score of 63.450.

Nastia Liukin, who is expected to challenge Johnson all the way through Beijing, was second after posting a 17.05 on the uneven bars that is the highest mark for an American woman in any event since gymnastics went to its new, open-ended scoring system two years ago.

Former world champion Chellsie Memmel, finally healthy after a devastating shoulder injury two years ago, showed she's still a factor, finishing third. Samantha Peszek was fourth. The finals are tomorrow night, and the top 12 qualify for the Olympic trials June 19-22 at the Wachovia Center, along with any gymnasts chosen by the selection committee. The top two at trials earn spots on the Olympic team.

The remaining four women will be chosen July 20 after a training camp at coach Bela Karolyi's ranch.

Noteworthy.

Shayla Worley, a member of the U.S. team that won the gold medal at last year's world championships, withdrew with a back injury.

The 17-year-old will petition for a spot at the Olympic trials. Only the top 12 women at nationals and athletes chosen by the selection committee qualify for the trials.