PARIS, Jan 18 (Reuters) - Olympique Lyon missed out on an opportunity to open a provisional five-point lead at the top of the Ligue 1 standings when they were held to a goalless home draw by Evian Thonon Gaillard on Friday. Lyon have 42 points from 21 matches and lead Paris St Germain by three points before the big-spending Qatar-backed side travel to fourth placed Girondins Bordeaux on Sunday (2000 GMT).