Olympics-Cycling-Viviani leads as omnium heads for thrilling climax

By Martyn Herman RIO DE JANEIRO, Aug 15 (Reuters) - Italy's Elia Viviani took the lead after of the track cycling men's omnium as the multi-discipline event headed towards a thrilling conclusion later on Monday. After four of the six disciplines, Viviani was leading with 140 points, 14 more than overnight leader Thomas Boudat of France and Britain's Mark Cavendish. Reigning Olympic champion Lasse Norman Hansen of Denmark, who gained a maximum points haul in Sunday's 60-lap scratch race and 4km individual pursuit but messed up the elimination race, was fourth with world champion Fernando Gaviria fifth. Monday's early action was the individual time trial covering four laps of the track. Viviani's time of 57.749 seconds was good enough for third of 17 starters, the best among the medal contenders. Cavendish, who won four stages of the Tour de France last month and who is chasing a first Olympic medal, was looking ominously strong and focused. He put himself right in the mix on Sunday with a scintillating 4km individual pursuit, going second fastest, 11 seconds quicker than at the London world championships when a poor ride in the IP left his Rio selection hopes in danger. Cavendish was sixth fastest in the time trial. The flying lap is the penultimate discipline before the climax in the 160-lap points race where riders can earn points in sprints every 10 laps. At the London world championships in March, Gaviria, Roger Kluge and Australian Glenn O'Shea all ended on 191 points in a nerve jangling finale, with Gaviria taking the title by virtue of having won two of the six elements. An equally tight battle is likely to decide gold here. Britain have won four of the six track golds in Rio. (Reporting by Martyn Herman, editing by Neil Robinson)