TOKYO, Aug 5 (Reuters) - The women's solo "kata" competition kicked off karate's first foray into the Olympics on Thursday with the 10 karateka performing routines in a hushed, spectator-less Nippon Budokan arena, the spiritual home of Japanese martial arts in Tokyo.

At the conclusion of the elimination rounds, it seemed clear the contest for the gold medal would be - as widely expected - between Japan's Kiyou Shimizu and Spain's Sandra Sanchez.

Their averages were 27.70 and 27.43, respectively, head-and-shoulders above the rest, while their tied, table-topping scores in the ranking rounds confirmed them as the finalists.

As the two "queens of kata" performed, photographers got busier, their camera shutters adding to the only other sounds of the competitors' snap-cracking dogi and mid-routine shouts.

In kata, practitioners demonstrate offensive and defensive techniques against a virtual opponent, choosing from 102 forms with esoteric-sounding names like Chatanyara Kushanku and Suparinpei that they yell out before they begin.

The execution of the three-minute kata, which come from the four main styles of karate - Goju-Ryu, Shito-Ryu, Shotokan-Ryu and Wado-Ryu - is scored based on speed, rhythm, balance, sharpness and other factors.

The first of the three-day tournament also includes the "kumite" sparring discipline in the men's -67kg and women's -55kg categories.