Megeve - Chris Froome's inexorable march towards a third Tour de France title continued apace on Thursday as he won the 18th stage uphill time-trial.
For more than an hour and a half, Dutchman Tom Dumoulin sat in the hot seat as his time of 31min 04sec remained unbeaten.
But, starting last of 179 riders, Froome gauged his effort to perfection to storm through and take the 17km time-trial in a time of 30:43.
Having been only fifth fastest at the first time-check after 6.5km, Froome got stronger as he went and was a clear winner by 21sec.
Italian Fabio Aru took a surprise third place, edging out Richie Porte of Australia by a fraction of a second.
But both gained significant time on those around them and Porte, who started the day two minutes off second place, is now only 1:08 behind Bauke Mollema.
The Dutchman lost 1:25 to Froome but remains second overall at 3:52.
Yet he was the slowest of the riders placed second to sixth and while Froome has as good as wrapped up overall victory, the fight for a podium finish is set to rage on the next two Alpine stages.
Romain Bardet in fifth also gained significant time on Mollema and young Briton Adam Yates, who is third at 4:16.
It was even a relatively successful day for out-of-sorts Colombian Nairo Quintana.
Second to Froome in 2013 and 2015, the 26-year-old Quintana was expected to be favoured by this year's course and many thought he should even be considered the favourite.
But he's been a long way off his best form and unable to react when Froome has put on the after-burners.
He held onto fourth place but gained time on both Mollema and Yates -- although, losing ground to Bardet and Porte.
Starting 136th of 179 riders, Dumoulin had already taken the top time by the end of the Cote de Domancy -- a steep climb inside the first 6.5km.
Belgian Thomas De Gendt had the best time up until Dumoulin set off but the Dutchman had put 41sec into the Lotto Soudal rider by the finish.
Dumoulin's main competition was always likely to come from the final group of riders, the climbing specialists.
Yet only Porte had beaten Dumoulin's time on the initial climb, albeit only by 9sec.
Yates started strongly and was third at 10sec with Froome only fifth at 23sec.
Quintana's miserable Tour was simply getting worse and he was 47sec off Porte's pace.
By the second time-check 10km in, Porte had dropped to second, now 10sec behind Dumoulin, and only a fraction of a second ahead of Froome, now up to third.
Yates, though, had dropped off remarkably and was more than 40sec behind.
At the third time-check, Froome had motored into the lead, 13sec ahead of Dumoulin with Porte at 22sec while Yates was going backwards quickly, now over a minute behind.
By the finish, there was no doubt who was in charge and Froome even punched the air in delight as he crossed the line.
Aru had got stronger as the time-trial went on and managed to pip Porte for third while Bardet had also timed his effort well to finish fifth.
Quintana limited his losses by coming in 10th but Mollema and Yates had dropped off dramatically.