Stybar, who had arrived at Roubaix velodrome as one of the three race leaders, rode high on the track in an attempt to tactically outwit the faster Greg van Avermaet... but almost came a cropped when a fan appeared to knock him off balance.
The Czech cyclist was seen to wobble, but only on closer inspection did it become apparent that a supporter, leaning over the barrier, had caused the incident.
Whether the fan's actions were a deliberate attempt to disrupt the rider is unclear, but Stybar had riled supporters at the race by not working with his breakaway cohorts to save his legs for the final sprint. And Stybar's Belgian team-mate, Yves Lampaert, said that the incident was "conscious" and "deliberate".
Fortunately for Stybar he was able to keep control of the bike, but couldn't get the better of Van Avermaet in the closing sprint, finishing second.
It wouldn't have been the first time that Stybar had seen his Paris-Roubaix hopes dashed by a fan. In 2013 the Czech rider was caught by an amateur photographer and crashed out of the lead group.
And this year's incident followed hot on the heels of the big crash in the Tour of Flanders that saw Van Avermaet and Peter Sagan's hopes of winning dashed by a fans' jacket that was dangling over the race barriers.
Read the original article on Eurosport: Did a fan try to grab Stybar in Paris-Roubaix?