Marcel Kittel has won stage seven of the Tour de France

Kittel edged out Norwegian Edvald Boasson Hagen by the narrowest of margins after making a huge lunge to the line, with Team Sunweb's Michael Matthews coming home in third.

Team Sky's Froome crossed safely in the pack to retain his 12-second lead over team-mate Geraint Thomas in the general classification, with Astana's Fabio Aru third, 14 seconds down.

Kittel's Quick-Step Floors sprint train had the dominant position as they barrelled towards the finish line in Nuits-Saint-Georges, but veteran Mark Renshaw guided Boasson Hagen to the front for Team Dimension Data.

Kittel risked finding himself boxed in behind Katusha-Alpecin's Alexander Kristoff but produced the burst of power he needed to take his third victory of this Tour, and 12th of his career in the race, after also winning stages two and six.

"When I crossed the line, I really had no clue if I won or not," the German said. "Before the finish, I knew it was going to be close. At 150m to go, I thought it was still 200, but luckily, the door opened on the right side and I could pass Edvald.

"To reach 12 stage wins at the Tour is an incredible success. I'm in a great shape. I'm super happy. The lead out was great. It's just crazy. I already have three wins in this Tour. I'm so happy about that."

British sprinter Dan McLay finished 10th for Fortuneo-Oscaro.

The threat of crosswinds on the 213.5-kilometre route from Troyes ensured Froome will not have been as relaxed as he was on Thursday's sedate stage through Champagne country, but the peloton stayed in one piece to ensure the yellow jersey was never under threat.

A four-man breakaway was allowed to go early as Manuele Mori (UAE Team Emirates), Yohann Gene (Direct Energie), Dylan van Baarle (Cannondale-Drapac) and Maxime Bouet (Fortuneo-Oscaro) headed up the road.

Their advantage got close to four minutes but they were given no more rope than that with the sprint trains wary of possible winds later in the stage.

Those gusts began to blow in the final 40 kilometres and the gap plummeted with several teams battling for position - sprint trains chasing stage honours and the general classification squads trying to keep their main men safe.

The break was caught with six kilometres left and the sprint trains stepped up their battle for supremacy at the front.

It took several minutes for the photo finish to confirm Kittel as the winner, and even then not everyone was convinced.

"It looks like Eddy's got it, no?" Froome said when shown the freeze frame. "I think Eddy's in front.

"That's sprinting for you. It can be really close. It's a huge shame for Eddy, but Marcel Kittel has got a lot of class and to lose to him is not bad."

Final leading positions after Stage 7 (Troyes - Nuits-Saint-Georges - 213.5km): 1 Marcel Kittel (Ger) Quick-Step Floors 05hrs 03mins 18secs, 2 Edvald Boasson Hagen (Nor) Dimension Data, 3 Michael Matthews (Aus) Team Sunweb, 4 Alexander Kristoff (Nor) Katusha-Alpecin, 5 John Degenkolb (Ger) Trek-Segafredo, 6 Dylan Groenewegen (Ned) Team LottoNl-Jumbo, 7 Rudiger Selig (Ger) Bora-Hansgrohe, 8 Nacer Bouhanni (Fra) Cofidis, Solutions Credits, 9 Andre Greipel (Ger) Lotto Soudal, 10 Daniel Mclay (GBr) Team Fortuneo - Oscaro, 11 Arnaud Demare (Fra) FDJ, 12 Rick Zabel (Ger) Katusha-Alpecin, 13 Lilian Calmejane (Fra) Direct Energie, 14 Oliver Naesen (Bel) AG2R La Mondiale, 15 Andrea Pasqualon (Ita) Wanty - Groupe Gobert, 16 Jack Bauer (NZl) Quick-Step Floors, 17 Reinardt Janse Van Rensburg (RSA) Dimension Data, 18 Sonny Colbrelli (Ita) Bahrain-Merida, 19 Grega Bole (Slo) Bahrain-Merida, 20 Pieter Vanspeybrouck (Bel) Wanty - Groupe Gobert all at the same time

Selected Others: 28 Simon Yates (GBr) Orica-Scott, 38 Nicolas Roche (Irl) BMC Racing Team, 39 Luke Rowe (GBr) Team Sky, 45 Geraint Thomas (GBr) Team Sky, 48 Christopher Froome (GBr) Team Sky, 57 Daniel Martin (Irl) Quick-Step Floors, 77 Ben Swift (GBr) UAE Team Emirates all at the same time, 128 Scott Thwaites (GBr) Dimension Data at 20secs, 152 Stephen Cummings (GBr) Dimension Data at 01mins 12secs,

General Classification after Stage 7: 1 Christopher Froome (GBr) Team Sky 28hrs 47mins 51secs, 2 Geraint Thomas (GBr) Team Sky 12secs, 3 Fabio Aru (Ita) Astana Pro Team at 14secs, 4 Daniel Martin (Irl) Quick-Step Floors at 25secs, 5 Richie Porte (Aus) BMC Racing Team at 39secs. 6 Simon Yates (GBr) Orica-Scott at 43secs, 7 Romain Bardet (Fra) AG2R La Mondiale at 47secs, 8 Alberto Contador (Spa) Trek-Segafredo at 52secs, 9 Nairo Quintana (Col) Movistar Team at 54secs, 10 Rafal Majka (Pol) Bora-Hansgrohe at 01mins 01secs, 11 Rigoberto Uran (Col) Cannondale-Drapac at the same time, 12 Pierre Latour (Fra) AG2R La Mondiale at 01mins 07secs, 13 Louis Meintjes (RSA) UAE Team Emirates at 01mins 24secs, 14 Emanuel Buchmann (Ger) Bora-Hansgrohe at 01mins 29secs, 15 Jakob Fuglsang (Den) Astana Pro Team at 01mins 33secs, 16 Mikel Landa (Spa) Team Sky at 01mins 47secs, 17 Tim Wellens (Bel) Lotto Soudal at 01mins 51secs, 18 Michal Kwiatkowski (Pol) Team Sky at 01mins 56secs, 19 Andrew Talansky (USA) Cannondale-Drapac at 01mins 57secs, 20 Serge Pauwels (Bel) Dimension Data at 02mins 00secs

Selected Others: 21 Nicolas Roche (Irl) BMC Racing Team at 02mins 14secs, 138 Scott Thwaites (GBr) Dimension Data at 20mins 22secs, 143 Ben Swift (GBr) UAE Team Emirates at 21mins 09secs, 152 Daniel Mclay (GBr) Team Fortuneo - Oscaro at 22mins 50secs, 164 Stephen Cummings (GBr) Dimension Data at 25mins 58secs, 191 Luke Rowe (GBr) Team Sky at 41mins 47secs