Michael Matthews (top) came in third.
Enough of the flat routes, Stage 8 kicks into the Jura mountains with a nice leg warmer ahead of the ninth test - which will be a real brute.
Get prep sports breaking news alerts from the Gwinnett Daily Post staff delivered to your email. "With these flat sprints there is not even a climb through the stage, so it's hard".
Only this time, the German made his move almost too late and edged Edvald Boasson Hagen of Norway only in a photo finish to win his third stage - and second in two days - in the race on Friday.
Kittel's victory sees the 29-year-old German draw level with Greipel's tally of eleven career stage wins on the Tour. It wasn't the win, but for us it felt like a win.
Matthews shared his thoughts after the finish.
"It's an incredible success", Kittel said.
Boasson Hagen, assuming sprinting duties for Dimension Data after Mark Cavendish's broken shoulder forced him out, looked to have beaten the German after a superb lead-out from Reinardt Janse van Rensburg. Sagan's team also lodged an appeal against the UCI race jury to the Court of Arbitration for Sport that was dismissed.
Chris Froome finished in the peloton, meanwhile, on a trouble-free day, to keep the yellow jersey, and Simon Yates likewise stays in white.
Team Sky and Froome were spared the work of leading the peloton once again as the sprint teams took responsibility for chasing down the breakaway, finally making the catch inside the last three kilometres.More news: North Korea will pay for its recent missile test
Stage seven (213.5km) from Troyes to Nuits-Saint-Georges is expected to be another transfer day for the general classification contenders leading into Sunday, where the tour fancies are tipped to make a move.
"That's the most relaxing day in the Tour I've ever had", Froome said after five hours in the saddle.
"In the end it is sprinting. And I think I've just got to do the same, basically, to be up there with these guys".
The last climb Saturday "could shake things up a bit", Froome said.
"Then I knew I just had to hope the door was open on the right side and that I could pass him". We brought a team to do really good leadouts and it's a team that's used to do doing good leadouts with (former Team Sunweb sprinter) Kittel.
The German almost waited too late to make his move and edged Edvald Boasson Hagen of Norway by a fraction of an inch to win his third stage of the race, and second in two days.
Demare beat all his rivals for green in an intermediate sprint which Kittel chose to sit out.
Kittel has 197 points to Demare's 182.
"That penultimate stage a year ago was worse than being cut by a knife", said Aru.
"We'll definitely get a very good idea of who's really going well and above all who's climbing well", Thomas, now lying second overall after his spell in the Tour lead, said on Friday.