Rather than a bib number, Dathan Ritzenhein should have had a great big question mark stenciled across his singlet for yesterday's USA Cross Country Championships at Mission Bay Park.

NANCEE E. LEWIS / Union-Tribune Dathan Ritzenhein finishes in 35 minutes, 3 seconds to win the USA Cross Country Championships.

Forced to do the bulk of his training the past month on a treadmill because of an injury, Ritzenhein's left leg still was hurting just days ago.

“I was nervous,” he admitted. “I didn't expect to do that much.”

So what unfolds?

Feeling no pain, Ritzenhein pulled away from the field midway through the 12-kilometer race, winning in 35 minutes, 3 seconds. Jorge Torres of Boulder, Colo., finished a distant second in 35:29. Olympic Marathon Trials winner Ryan Hall placed fifth in 35:50.

“I didn't feel my leg at all,” Ritzenhein said. “It'll probably hurt like hell (today).”

Compared to women's 8K winner Shalane Flanagan's performance, the men's race was a virtual photo finish. Flanagan, who set two American records last year, appeared to be in summer track form, winning in 25:26. Rene Metivier of Boulder placed second, 70 seconds back, in 26:36.