Primoz Roglic won stage 17 of the Tour de France to Serre-Chevalier as Chris Froome finished third to tighten his grip on the yellow jersey.
Slovenian Roglic led by 90 seconds at the top of the Galibier and the former junior world ski jump champion showed no fear on the long fast descent to the finish to win by 73 seconds.
Rigoberto Uran finished second to take six vital bonus seconds in the close battle for yellow, with Froome taking four for this third place by pipping Romain Bardet to the line.
Three-time Tour winner Froome now leads by 27 seconds, with Colombian Uran and Frenchman Bardet tied for second place. Fabio Aru, who was second in the general classification, finished well behind the yellow jersey group to drop to 10th.
The green jersey leader, who had won five stages on this year's tour, tumbled during the first climb of the stage.
Kittel tried to soldier on but eventually had to call it quits.
It means that Michael Matthews is the favourite to win the green jersey.
1. Chris Froome 73h 27' 26''
2. Rigoberto Uran + 00' 27''
3. Romain Bardet + 00' 27''
1. Michael Matthews 364
2. Andre Greipel 204
3. Alexander Kristoff 158
King of the Mountain:
1. Warren Barguil 129
2. Primoz Roglic 80
3. Thomas de Gendt 61
1. Simon Yates 73h 31' 33''
2. Louis Meintjes + 02' 28''
3. Emanuel Buchmann + 22' 59''