In 2003 Levon Aronian won the Finet Chess960 Open at Mainz; this qualified him for a match against Chess960 "World Champion" Peter Svidler at Mainz the following year, a match which he lost 4.5-3.5. He won the Finet Chess960 Open tournament again in 2005 which earned him a rematch with Svidler in 2006, and won the match this time 5-3 to become Chess960 World Champion. In 2007 he successfully defended his title of Chess960 World Champion by beating Viswanathan Anand.
Chess960 games with Aronian and others:
www.chess-960.org/php/show_entries.php