Tour leader Lance Armstrong begins the 159.5km stage hoping to retain the yellow jersey

Riders observe a minute's silence in memory of Estonian cyclist Lauri Aus, who died in an accident on Sunday

A group of 15 riders make an early break from the peloton but are quickly caught

Kazakhstan's Alexandre Vinokourov (left), in third place overall, shadows second-placed Jan Ullrich (right)

Colombian Santiago Botero leads France's Sylvain Chavanel as the pair establish a nine-minute lead over the peloton

Stage 14 winner Gilberto Simoni is unable to make an impression on the leaders during stage 15

Armstrong's bike catches a spectator's bag, sending the American tumbling, while rival Ullrich narrowly escapes

Armstrong and Spanish rider Iban Mayo, who also fell, pick themselves up and quickly remount to get back into the race

Armstrong digs deep to produce an incredible fightback, overtaking Ullrich and heading for a stage win

The American crosses the finish line to win the stage and boost his chances of a fifth Tour title

An exhausted Ullrich crosses the finish line 40 seconds later in a thrilling end to the crucial stage

Armstrong answers his critics, retaining the yellow jersey and extending his overall lead to over a minute