It wasn’t just the heat and climb causing problems early on with the course technical enough at the finish to see both Jeremy Roy (FDJ) and Oliver Naesen (IAM Cycling) go crashing over the barriers on one of the final corners.

Lanterne Rouge Sam Bennett (Bora-Argon 18) was the first rider down the slope, but it was Alexis Gougeard (Ag2r-La Mondiale) who set the first notable mark – the Frenchman reaching the Megeve finish line in 33.06.

Cofidis’ Nicolas Edet was another climbing specialist out early, and set an average speed of 31.27km/h to take the mark to 32.37 but it continued to fall during the early parts of the race.

Portuguese time trial champion Nelson Oliveira (Movistar), Romain Sicard (Direct Energie) and Jerome Coppel (Cofidis) – the latter the first man to break the 32-minute mark – all had short spells in the hot seat.

Spanish champion Ion Izaguirre (Movistar) showed he felt no need to leave anything in reserve by setting a new mark at the Cote de Domancy – where the €5,000 Prix Bernard Hinault was on offer – and at the finish line (31.46), but he too had only a short stint in the hot seat.

Romain Bardet responded well, however – ceding just a handful of seconds at the finish line though Nairo Quintana was more than 30 seconds behind the two, after a couple of hairy moments on the corners.

Froome, meanwhile, was fifth at the first time check but improved as the climb went on – he was just ten seconds behind Dumoulin at the second time check and then went quickest at the third point.

Fellow Brit Adam Yates (Orica-BikeExchange) successfully defended his white jersey – conceding only a few seconds to Louis Meintjes (Lampre-Merida), and also just 12 seconds to Quintana in the race for a podium place.

Yates had actually started strongest of the three, but lost time on the latter parts of the course to finish in 32.06 – two seconds quicker than second-placed Bauke Mollema (Trek-Segafredo).

Froome’s charge continued, however – the yellow jersey had just 1500m left to ride as Mollema finished – Dumoulin seemingly accepting his fate in the hot seat.

The Team Sky man stopped the clock in 30 minutes and 43 seconds to gain more than a minute on second-placed Mollema, third-placed Yates and fourth-placed Quintana as his charge towards a third yellow jersey continues.

Tour de France 2016: stage 18 (ITT) – result

1) Chris Froome (GBR) – Team Sky – 30.43
2) Tom Dumoulin (NED) – Giant-Alpecin +21”
3) Fabio Aru (ITA) – Astana +33”
4) Richie Porte (AUS) – BMC Racing – ST
5) Romain Bardet (FRA) – Ag2r-La Mondiale +42”
6) Thomas de Gendt (BEL) – Lotto-Soudal +1.02
7) Ion Izagirre (ESP) – Movistar +1.03
8) Joaquim Rodriguez (ESP) – Katusha +1.05
9) Louis Meintjes (RSA) – Lampre-Merida +1.08
10) Nairo Quintana (COL) – Movistar +1.10

General classification

1) Chris Froome (GBR) – Team Sky – 77.55.53hrs
2) Bauke Mollema (NED) – Trek-Segafredo +3.52
3) Adam Yates (GBR) – Orica-BikeExchange +4.16
4) Nairo Quintana (COL) – Movistar +4.37
5) Romain Bardet (FRA) – Ag2r-La Mondiale +4.57
6) Richie Porte (AUS) – BMC Racing +5.00
7) Fabio Aru (ITA) – Astana +6.08
8) Alejandro Valverde (ESP) – Movistar +6.37
9) Louis Meintjes (RSA) – Lampre-Merida +7.15
10) Daniel Martin (IRL) – Etixx-QuickStep +7.18