Carpet tacks spread on the road brought the first Pyrenees stage of the Tour de France to a near standstill and prompted the bunch to call a truce in the fight for places.
Defending champion Cadel Evans was one of some 30 riders in the 50-strong peloton to suffer punctures because of the tacks which race officials said had been scattered deliberately.
The 14th-stage win went to Spain's Luis Leon Sanchez, who broke from a group of escapees 11 kms from the line to cross it on his own and collect the fourth Tour stage laurels of his career.
Green jersey holder Peter Sagan finished second ahead of Frenchman Sandy Casar at the end of the 191-km ride from Limoux but the real action was taking place at the back where riders encountered the tacks as they began the descent of the first-category Mur de Peguere, 38.5 kms from the finish.
"'It was obviously done on purpose. We have the tacks but we don't know who spread them,'' said race director Jean-Francois Pescheux.
Evans suffered a puncture at the top of the pass. His BMC team car was already speeding down the descent and team mate Tejay Van Garderen passed without noticing him so the Australian was left unattended for several minutes and had to wait for another team mate to give him his back wheel.
On the descent, Evans finally managed to change bikes but it was a tricky process during which team manager Jim Ochowicz twice fell into a roadside ditch.
To make matters worse, Evans punctured again with 12 kms to go.
"Yellow jersey holder Bradley Wiggins realised something was wrong and went to the front of the group to tell them to slow down.
"When 15 or 16 guys puncture, it becomes really apparent that something happened,'' said Wiggins.
"Evans and the rest managed to come back in the descent and everything went back to normal,'' Pescheux said.
Team Sky manager Dave Brailsford said it was only normal to wait for rivals when they were stopped by obvious acts of vandalism.
"There were definitely tacks on the road. It was the right decision. You never know what's going to happen to you. What goes around comes around,'' he said.
As a result of the lull, all the Tour contenders finished together and the overall standings did not change.
Wiggins retained his overall lead of two minutes five seconds on team mate Chris Froome while Italy's Vincenzo Nibali stayed in third, 2:23 adrift. Evans is still fourth, 3:19 off the pace.
Tacks being spread on the course of the Tour is nothing new. It was common practice in the early days of the race and it happened again in 1996, when several race cars were halted by nails.
Before Friday's problems, no real attacks had taken place against Wiggins or Team Sky and the Mur de Peguere was tackled with world champion Mark Cavendish, by no means a climber, leading the way.
The peloton had seemed content to let the breakers led by Leon Sanchez, Sagan, Casar and Belgium's Philippe Gilbert take a 17-minute lead and go all the way.
For Sanchez, the stage win came as a huge relief as he injured his wrist early in the Tour.
"I crashed in the beginning of the Tour and I was unlucky in the couple of breaks I joined. I'd started to doubt but today I picked the right tactics,'' said Sanchez, who went ahead on his own to avoid being outsprinted on the line by the faster Sagan.
Tomorrow's 15th stage takes the pack from Samatan to Pau over 158.5 kms.
Will Shane Cameron beat Kali Meehan on Saturday?