Mark Cavendish's challenge for the Tour de France green jersey could be over less than one week into the race after Alessandro Petacchi won the fourth road stage into Reims today.
Petacchi (Lampre-Farnese) won his second stage of the 2010 Tour, but Cavendish was left well adrift of points classification leader Thor Hushovd (Cervelo Test Team) on the 153.5kilometres stage from Cambrai to Reims after his HTC-Columbia lead-out train disintegrated in the closing kilometres.
Petacchi, who won the opening road stage in Brussels on Sunday, finished ahead of Julian Dean (Team Garmin-Transitions) and Team Sky's Edvald Boasson Hagen in second and third, respectively.
Hushovd finished ninth, while Cavendish was 12th in a stage he had hoped to win.
The 25-year-old from the Isle of Man had planned an assault on the maillot vert after reaching Paris for the first time in 2009 - when he won six stages - but finished 10 points behind Hushovd in the sprinters' classification.
After being shaken up on the cobbles on stage three yesterday, the general classification standings were unchanged with Fabian Cancellara (Team Saxo Bank) retaining the yellow jersey.
Geraint Thomas (Team Sky) remained second overall and in the best young rider's white jersey, with Cadel Evans (BMC Racing) third.
Tour favourite Alberto Contador (Astana) was in ninth place after five days, with Team Sky leader Bradley Wiggins 14th and Team RadioShack counterpart Lance Armstrong in 18th.