Cavendish, who has 30 career stage wins in the Tour, was impressed with his power in the sprint where he placed 10th in Chartres, but said that matching his rival isn't possible.
"I was following quite good wheels, but it was choppy," Cavendish explained. "I was picking wheels and I seemed to be good. But now when I go, like I said, Quick-Step and Bora are at a different kind of top speed.
"I thought when I kicked in the last metres, I was floating. I was quite excited! Actually, I looked at me power and it was quite good! But I'm not going to match them."
Cavendish rode the wheels of Dimension Data into the final kilometres, with Mark Renshaw doing the last bit of work. He then hopped on the wheel of Alexander Kristoff (UAE-Team Emirates) but could not match eventual winner Dylan Groenewegen (LottoNL-Jumbo).
"That pinch point [at the corner at two kilometres out] messed up a lot of lead-out trains. There were a few renegades about but then you just slotted in," Cavendish added.
"The speed was super high. I jumped from wheel to wheel and actually I was moving well. Until two hundred metres to go I felt good and was happy. Even my power was good."
The sprint came at the end of a 231-kilometre stage, the longest of the 2018 race.
Cavendish is coming back to his best after early season crashes that resulted in broken ribs. He repeated what he has said in previous days that his "back is against the wall" with the lead-up he has had.
"I'll keep trying," he added. "It's not going to be easiest for use to win here but all we can do is try. We keep doing that, we have a great morale in the team."
"He's OK," said the team's performance manager, Rolf Aldag. "You say he used to win six stages in the Tour, but now there's more competition and it's challenging for everyone.
"He's participating in the sprints now and the first two days were really difficult as a team We hope to get better, get the routine in place, and keep participating in the sprints. There's more to come."
Dutchman Dylan Groenewegen won on the Champs-Élysées in 2017 and today he blasted by Colombian Fernando Gaviria, winner of two stages so far in his debut Tour.
"There's not a lot to say," said Quick-Step team boss, Patrick Lefevere. "The team was there in the finish, the order was not to sprint too early because it was going uphill. Tou should wait until 100 metres until the finish, but if you wait too long you will be closed against the barriers.
"But we knew that, at least I knew, that if it was a flat stage like tomorrow and today then Dylan was the most dangerous.
"What could Gaviria do differently? If you lose by five centimetres, you can say you could've done something differently, but if you lose by three bike lengths, then there's no discussion."
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