"It's definitely the closest win I've ever had in my career", said the 29-year-old Kittel.
"It is insane and celebrating three stage wins is incredible".
Meintjes was also in third place in the young riders' classification, 41 seconds behind British leader Simon Yates (Orica-Scott).
The previous pile-ups will mean it promises to be a nervy stage, and even more so in the run-in to the finish as riders jostle for position and the pace increases and tension intensifies.
After a 25km transfer to the start this morning, my BMC squad were one of the first teams to arrive so instead of sitting on a stuffy team bus we all chose to go to the sign-on early.
"I am in great shape and super happy the team supported me".
Frenchman Arnaud Demare (FDJ) and Andre Greipel (Lotto Soudal) followed Kittel across the Troyes finish line, while Chris Froome (Sky) retained the yellow jersey and a 39-second general classification buffer on Porte (fifth).
"I haven't raced much this year, I'm fresher at this part in the season and I hope in the third part of the Tour get better".
Froome's post-race press conference was limited to just three questions with time getting late and the Sky team bus having already left without him.
Earlier, a three-man breakaway had set off inside the first kilometre but with more than 200km to ride on a pan-flat stage with powerful sprinters' teams controlling the gap, it was always doomed to fail.
"It's an incredible feeling to be back in yellow, but having said that I know race far, far from over, it's only just begun for me", said Froome.
Froome is predicting a "decisive" day tomorrow during the ninth stage, a 181.5km mountain route from Nantua to Chambéry. For Froome, the results from this weekend might make a big difference. You get the big points for that and then you have to see. Hors Category means they're steeper and longer than any other climbs in the Tour, so this weekend will suit my climbing cousin Dan Martin.
"The situation is different to the last years for sure", he said, referring to Sagan winning the green jersey in each of the last five years.
- France to Ban Sales of Gas, Diesel Vehicles by 2040
- Hackers Have Been Targeting US Nukes
- Why Is Tesla's Stock Down?
- EU, Japan agree on free-trade deal
- 18 states sue Betsy DeVos for failing to implement student loan protections
- Amelia Earhart May Have Survived Crash-Landing, Newly Discovered Photo Suggests
- Rob Kardashian cuts Blac Chyna off
- Nintendo Switch Online Smartphone App Launches On 21st July
- +220000 Jobs in June; Record 153168000 Employed
- Trump says Russian Federation likely hacked but nobody 'knows for sure'