By Pritha Sarkar

RIO DE JANEIRO (Reuters) - It took four Olympics but flamboyant showman Fabian Hambuechen was finally leaping with joy after he soared past his rivals to become the first German gymnast in 20 years to strike gold with an electrifying routine on the high bar on Tuesday.

"It’s just indescribable right now," said Hambuechen who now has a full set of Olympic horizontal bar medals after picking up silver in 2012 and bronze in 2008.

"I said before that this would be my last competition... and to finish it like that is just a dream come true.

"That (gold) was the only medal which wasn’t mine until now but I made it, I’m just overwhelmed.”

The 28-year-old was the first to mount the bar and he showed no fear as he pulled off four high-flying release-and-catch moves.

Two full twisting somersaults over the bar -- a Cassina followed by a Kolman -- proved to be the highlights of a routine that ended with the German winding his arms backwards to steady his feet on dismount.

However, the man who used to fly through the air wearing spectacles when he made his Olympic debut in 2004 faced an anxious wait to see if any of the remaining seven finalists would surpass his score of 15.766.

Up next was his biggest threat, flying Dutchman Epke Zonderland.

Zonderland had turned Hambuechen's golden dreams into silver four years ago but the 2012 champion's hopes of a repeat triumph came crashing down as he lost his grip while attempting a heart-stopping Cassina into a Kovacs combination.

Falling flat on his face, with his arms outstretched and legs splayed on the mat, Zonderland was a vision of defeat as he lay still for several seconds.

Britain's Nile Wilson was caught saying "No way" as he waited for Zonderland to get back on his feet. Although the 30-year-old remounted the bar, he knew there would be no place for him on the podium and he finished seventh with 14.033.

"I timed it a little bit wrong. I almost got it and I thought I had it, that's why I tried to stick on the bar but I slipped away and I fell on my tummy," Zonderland explained.

Zonderland's misfortune allowed American Danell Leyva to pick up his second silver of the day after also finishing second on the parallel bars.

While Leyva kissed his chalk-covered knuckles on completing his dismount, his stepfather and coach Yin Alvarez was off sprinting down the dugout for the second time on Tuesday, high-fiving gray-suited officials.

Wilson grabbed a sixth medal in gymnastics for the British team when he claimed bronze with 15.466.

(Reporting by Pritha Sarkar, additional reporting by Chris Gallagher and Mark Trevelyan; editing by Jan Harvey and Clare Fallon)