A Russian mathematician's solution to a 100-year-old math puzzle was voted Breakthrough of the Year by Science, a leading scientific journal.

Grigori Perelman, in articles published on the Internet more than three years ago, claimed to have solved Poincare's conjecture, a mathematical puzzle identified in 1904 by the French mathematician Henri Poincare, the Independent said Friday.

His proposed solutions to the conjecture were validated by other mathematicians in the field of topology, which is the science of surfaces.

"While bringing new results to topology, Perelman's work brought new techniques to geometry," said Science in announcing the award. "It cemented the central role of geometric evolution equations, powerful machinery for transforming hard-to-work-with spaces into more-manageable ones."

Earlier this year, Perelman won the highest honor in mathematics, the Fields Medal, but refused to accept it, and a separate $1 million prize offered by the Clay Mathematics Institute in Massachusetts.

Perelman lives in St. Petersburg.

Copyright 2006 by United Press International