Former world champion Viswanathan Anand defeated Russian Grandmaster Vladimir Kramnik in the first game of their four-game match for the Sparkassen Trophy here.
Playing with white pieces, Anand needed 66 moves to beat Kramnik late on Wednesday in a match played as part of the "No-Castling" Chess devised by the Russian GM.
Castling is not allowed in this format in an effort to make the game more interesting.
Castling is a special move to protect the king and activate the rook. It's the only time in chess a player can move two pieces in one move.
The Indian maestro will take on Kramnik, also a former world champion, in the second game on Thursday night.
Anand had returned to over-the-board action in the Croatia Grand Chess Tour tournament in Zagreb last week.
He finished second overall (Rapid and Blitz combined) in that event.