Greipel came a close second to Peter Sagan (Tinkoff), who clashed with Arnaud Demare (FDJ) in the finishing straight.
He said he had been caught behind Michael Matthews (Orica-BikeExchange) who crashed and was fortunate to escape with just abrasions.
Greipel said: “I was behind the crash at 1km I was maybe 40th position. Jürgen Roelandts brought me up to the front again and I choose the wheel of Sagan.
“He was fighting with Demare, I though they were going to crash at one point. So I hesitated a little bit and if you lose by one cm you are not first and that is sport.”
He added: “If you come back from 1km to go from 40th position you are not fresh at all, you have to wait and time it. I timed it wrong in the end.”
The German sprinter added that his team had been the “only team” to “take responsibility” for chasing down the day’s breakaway and that had depleted his lead-out train for the final kilometres.
Sagan offered a similar assessment of his win saying he was fortunate that Greipel ran out of road to get ahead.
“After I start my sprint André was behind me and he starts to sprint also, maybe a bit later, and that’s why I won because he passed me very fast but it was already finished. I was a bit lucky today,” he said.