HELSINKI, Finland — Bryan Clay doesn't dare look over his shoulder. Straight ahead is the only direction he'll consider.

Midway through the decathlon at the 10th World Championships of Track and Field — five events done, five to go — the Castle High alum is out in front.

But his margin is a slender 14 points — and the commanding presence breathing down his back is that of Roman Sebrle, who beat Clay for the gold medal in the 2004 Olympics in Athens.

"No predictions; we all know that anything can happen in a decathlon," said Clay, 25, Hawai'i's first Olympic (silver) medalist in track and field.

Clay wrapped up day one of the worlds with a 4,527-point score at Olympic Stadium.

Czech Republic's Sebrle, world record-holder and the only man in track history to total more than 9,000 points (9,026 in a 2001 meet), is a close second at 4,513. Estonia's Kristjan Rahnu (4,404), Russia's Aleksandr Pogorelov (4,344) and Hungary's Attila Zsivoczky (4,330) are not far off the pace.

Small as it is, Clay's lead over Sebrle is a promising sign, perhaps even an omen.

Sebrle led Clay through those first five events in Athens, and went to take the gold with 8,893 points to Clay's 8,820.

"Some events went better today (than expected), some not, but you know, this is a decathlon," Clay said.

The fifth and final event of the day showed Clay at his grittiest best.

Running through a steady, pelting rain, and doing so out of the tough lane seven, with lane eight vacant and no one to focus on, Clay clocked 47.78 in the 400 meters that was the fastest of his life in decathlon competition.

Earlier, Clay unleashed a shot put of 53 feet, 3 1/4 inches that was another personal best.

And he opened with a blazing 10.43 victory in the 100-meter dash, worth 992 points for his best individual-event score.

But two events were on the disappointing side, each far behind his career bests: a long jump of 24 feet, 9 inches and a high jump of 6 feet, 6 3/4 inches.

All told, Sebrle beat Clay three events to two, but Clay's margin of supremacy in those two kept him in the overall lead.

Sebrle's advantages came in the long jump (25-9 1/2), shot put (53-5 1/2) and high jump (6-9).

That high jump performance — as the rain created serious traction problems — gave Sebrle the temporary overall lead before Clay surged back in front after the 400.

Clay barely missed with the high jump bar set at 6-8, lofting his torso over the crossbar but skimming it off with his calves on the way down.

And now it's on to the day two schedule: 110-meter high hurdles, discus throw, pole vault, javelin throw and 1,500-meter run.

Clay is the world record-holder in the decathlon discus throw and is considered a better hurdler than Sebrle.

The Czech star, though, has enjoyed past advantages over Clay in the javelin and 1,500. Thus, the pole vault may prove to be the decisive event.

With his 2004 Athens gold and silver at Sydney in 2000, Sebrle's name is already secure in the Olympic archives.

But he's never won at the World Championships, placing ninth in 1997, failing to finish in 1999, 10th in 2001, and second in 2003.

Then again, Clay has had even worse luck in previous worlds, bowing out with injuries in both 2001 and 2003.

"I'll have to fight to be able to beat Clay," Sebrle said. "He seems to be strong here."