By Lucinda Elliott MONTEVIDEO (Reuters) -Voters in South America's laid-back Uruguay, known for its beaches, legalized marijuana and stability, headed to the polls on Sunday for a second-round presidential race between moderates that closes out a bumper year for global elections.

The candidate of the conservative coalition that has governed for the past five years conceded defeat after a tight runoff, as Uruguay joined others around the world in rebuking the incumbent party in a year of landmark elections.