Roman Sebrle of the Czech Republic cemented his position as the world's greatest all-round athlete when he won the Olympic decathlon gold medal with an emphatic late surge on Tuesday.

The world-record holder and only man to break the 9,000 points barrier had trailed Kazakhstan's Dmitriy Karpov for much of the 10-discipline test but hit the front with a spectacular 70.52-metre javelin throw in the penultimate event.

That turned a 46-point deficit on Karpov into a 63-point lead over Bryan Clay of the United States and the experienced 29-year-old Sebrle then safely negotiated the 1,500 metres to add gold to the silver he won in Sydney four years ago.

His winning total was 8,893 points. Clay, 24, took the silver with 8,820 to continue his remarkable progress over the last two years while the 23-year-old Karpov won the bronze with 8,725.

Briton Dean Macey, back in action after three injury-ravaged years, repeated his fourth-place finish from Sydney with 8,414 points.

Sebrle timed his charge to perfection after Karpov had started the day well, the lean Kazak extending his lead to 166 points with exceptional performances in the 110 metres hurdles and discus -- both the best in the field.

Sebrle kept in touch, however, his 14.05-second hurdles and 48.72-metre discus scoring well, and was able to cut the deficit to a mere 46 points in a marathon four-hour pole vault with 5.00 metres to the 4.60 of Karpov.

The gold medal was effectively settled, as expected, in the javelin, one of the Czech's strongest events.

He opened with an impressive 68.95, followed up with 67.05 and then launched the spear 70.52 metres for 897 points.

Karpov could manage only 55.54 for a meagre 671, by far his worst performance of the competition, allowing Clay to sweep past him with a personal best 69.71 (885 points).

It even gave the young a American a shot at gold but he would have needed to beat the world record holder by nearly 10 seconds in the 1,500 -- an unlikely scenario as Sebrle's best over the distance bettered Clay's by 17 seconds.

Instead the American chose to shadow the master clear of danger for the three-and-three-quarter laps.

Sebrle finished in four minutes 40.01 seconds, 17 seconds short of what he needed for 9,000 points, but he was clearly delighted as he accepted the congratulations of his weary rivals. Clay, who had been the early pacesetter on Monday, had continued his solid work throughout the second day with an impressive 50.11 discus and a 4.90 pole vault, showing that his victory over world champion Tom Pappas in the U.S. trials was no fluke.

It was a disappointing day for Pappas, who was forced to drop out of the competition after aggravating a strain in his left foot during the pole vault, when he failed to register a height.

Defending Olympic champion Erki Nool was never a factor over the two days and his field-leading 5.40 pole vault was a rare bright spot for the Estonian, who eventually climbed to eighth overall.

Former world record holder Tomas Dvorak of the Czech Republic pulled out on Monday after aggravating an Achilles tendon injury during the opening event, the 100 metres.