Top contenders now include 35-year-old Russian Denis Menchov, a two-time Tour of Spain winner, the Schleck brothers and the 2008 Tour de France winner CarlosSastre of Spain.
"To me, it's obvious that Astana should have one leader and to me, that leader is Contador, " Riis -- whose CSC team won the race last year with CarlosSastre -- told reporters.
In the end, the sprint was a formality for Cavendish but, with the breakaway group finishing 41 seconds ahead of the peloton, Armstrong proved the big winner, gaining time on all his rivals including Astana team-mate and 2007 Tour winner Alberto Contador, defending champion CarlosSastre and Giro d'Italia winner Denis Menchov.